Eigen  5.0.1
 
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Eigen::SparseMatrixBase< Derived > Class Template Reference

#include <Eigen/src/SparseCore/SparseMatrixBase.h>

Detailed Description

template<typename Derived>
class Eigen::SparseMatrixBase< Derived >

Base class of any sparse matrices or sparse expressions.

Template Parameters
Derivedis the derived type, e.g. a sparse matrix type, or an expression, etc.

This class can be extended with the help of the plugin mechanism described on the page Extending MatrixBase (and other classes) by defining the preprocessor symbol EIGEN_SPARSEMATRIXBASE_PLUGIN.

+ Inheritance diagram for Eigen::SparseMatrixBase< Derived >:

Public Types

enum  {
  RowsAtCompileTime ,
  ColsAtCompileTime ,
  SizeAtCompileTime ,
  MaxRowsAtCompileTime ,
  MaxColsAtCompileTime ,
  MaxSizeAtCompileTime ,
  IsVectorAtCompileTime ,
  NumDimensions ,
  Flags ,
  IsRowMajor ,
  InnerSizeAtCompileTime
}
 
using RealScalar
 
using StorageIndex
 
using value_type
 
- Public Types inherited from Eigen::EigenBase< Derived >
using Index
 The interface type of indices.
 

Public Member Functions

template<typename CustomBinaryOp, typename OtherDerived>
constexpr const CwiseBinaryOp< CustomBinaryOp, const Derived, const OtherDerived > binaryExpr (const Eigen::SparseMatrixBase< OtherDerived > &other, const CustomBinaryOp &func=CustomBinaryOp()) const
 
template<int NRows, int NCols>
constexpr FixedBlockXpr< NRows, NCols >::Type block (Index startRow, Index startCol)
 
template<int NRows, int NCols>
constexpr const ConstFixedBlockXpr< NRows, NCols >::Type block (Index startRow, Index startCol) const
 This is the const version of block<>(Index, Index).
 
template<int NRows, int NCols>
constexpr FixedBlockXpr< NRows, NCols >::Type block (Index startRow, Index startCol, Index blockRows, Index blockCols)
 
template<int NRows, int NCols>
constexpr const ConstFixedBlockXpr< NRows, NCols >::Type block (Index startRow, Index startCol, Index blockRows, Index blockCols) const
 This is the const version of block<>(Index, Index, Index, Index).
 
template<typename NRowsType, typename NColsType>
constexpr FixedBlockXpr<...,... >::Type block (Index startRow, Index startCol, NRowsType blockRows, NColsType blockCols)
 
template<typename NRowsType, typename NColsType>
constexpr const ConstFixedBlockXpr<...,... >::Type block (Index startRow, Index startCol, NRowsType blockRows, NColsType blockCols) const
 This is the const version of block(Index,Index,NRowsType,NColsType)
 
template<int CRows, int CCols>
constexpr FixedBlockXpr< CRows, CCols >::Type bottomLeftCorner ()
 
template<int CRows, int CCols>
constexpr const ConstFixedBlockXpr< CRows, CCols >::Type bottomLeftCorner () const
 This is the const version of bottomLeftCorner<int, int>().
 
template<int CRows, int CCols>
FixedBlockXpr< CRows, CCols >::Type bottomLeftCorner (Index cRows, Index cCols)
 
template<int CRows, int CCols>
const ConstFixedBlockXpr< CRows, CCols >::Type bottomLeftCorner (Index cRows, Index cCols) const
 This is the const version of bottomLeftCorner<int, int>(Index, Index).
 
template<typename NRowsType, typename NColsType>
constexpr FixedBlockXpr<...,... >::Type bottomLeftCorner (NRowsType cRows, NColsType cCols)
 
template<typename NRowsType, typename NColsType>
constexpr ConstFixedBlockXpr<...,... >::Type bottomLeftCorner (NRowsType cRows, NColsType cCols) const
 This is the const version of bottomLeftCorner(NRowsType, NColsType).
 
template<int CRows, int CCols>
constexpr FixedBlockXpr< CRows, CCols >::Type bottomRightCorner ()
 
template<int CRows, int CCols>
constexpr const ConstFixedBlockXpr< CRows, CCols >::Type bottomRightCorner () const
 This is the const version of bottomRightCorner<int, int>().
 
template<int CRows, int CCols>
constexpr FixedBlockXpr< CRows, CCols >::Type bottomRightCorner (Index cRows, Index cCols)
 
template<int CRows, int CCols>
constexpr const ConstFixedBlockXpr< CRows, CCols >::Type bottomRightCorner (Index cRows, Index cCols) const
 This is the const version of bottomRightCorner<int, int>(Index, Index).
 
template<typename NRowsType, typename NColsType>
constexpr FixedBlockXpr<...,... >::Type bottomRightCorner (NRowsType cRows, NColsType cCols)
 
template<typename NRowsType, typename NColsType>
constexpr const ConstFixedBlockXpr<...,... >::Type bottomRightCorner (NRowsType cRows, NColsType cCols) const
 This is the const version of bottomRightCorner(NRowsType, NColsType).
 
template<int N>
constexpr NRowsBlockXpr< N >::Type bottomRows (Index n=N)
 
template<int N>
constexpr ConstNRowsBlockXpr< N >::Type bottomRows (Index n=N) const
 This is the const version of bottomRows<int>().
 
template<typename NRowsType>
constexpr NRowsBlockXpr<... >::Type bottomRows (NRowsType n)
 
template<typename NRowsType>
constexpr const ConstNRowsBlockXpr<... >::Type bottomRows (NRowsType n) const
 This is the const version of bottomRows(NRowsType).
 
template<typename NewType>
constexpr CastXpr< NewType >::Type cast () const
 
constexpr ColXpr col (Index i)
 
constexpr ConstColXpr col (Index i) const
 This is the const version of col().
 
Index cols () const
 
constexpr ConjugateReturnType conjugate () const
 
template<bool Cond>
constexpr std::conditional_t< Cond, ConjugateReturnType, const Derived & > conjugateIf () const
 
const CwiseUnaryOp< internal::scalar_abs_op< Scalar >, const Derived > cwiseAbs () const
 
const CwiseUnaryOp< internal::scalar_abs2_op< Scalar >, const Derived > cwiseAbs2 () const
 
const CwiseUnaryOp< internal::scalar_arg_op< Scalar >, const Derived > cwiseArg () const
 
const CwiseUnaryOp< internal::scalar_cbrt_op< Scalar >, const Derived > cwiseCbrt () const
 
template<typename OtherDerived>
constexpr const CwiseBinaryEqualReturnType< OtherDerived > cwiseEqual (const Eigen::SparseMatrixBase< OtherDerived > &other) const
 
constexpr const CwiseScalarEqualReturnType cwiseEqual (const Scalar &s) const
 
template<typename OtherDerived>
constexpr const CwiseBinaryGreaterReturnType< OtherDerived > cwiseGreater (const Eigen::SparseMatrixBase< OtherDerived > &other) const
 
constexpr const CwiseScalarGreaterReturnType cwiseGreater (const Scalar &s) const
 
template<typename OtherDerived>
constexpr const CwiseBinaryGreaterOrEqualReturnType< OtherDerived > cwiseGreaterOrEqual (const Eigen::SparseMatrixBase< OtherDerived > &other) const
 
constexpr const CwiseScalarGreaterOrEqualReturnType cwiseGreaterOrEqual (const Scalar &s) const
 
const CwiseUnaryOp< internal::scalar_inverse_op< Scalar >, const Derived > cwiseInverse () const
 
template<typename OtherDerived>
constexpr const CwiseBinaryLessReturnType< OtherDerived > cwiseLess (const Eigen::SparseMatrixBase< OtherDerived > &other) const
 
constexpr const CwiseScalarLessReturnType cwiseLess (const Scalar &s) const
 
template<typename OtherDerived>
constexpr const CwiseBinaryLessOrEqualReturnType< OtherDerived > cwiseLessOrEqual (const Eigen::SparseMatrixBase< OtherDerived > &other) const
 
constexpr const CwiseScalarLessOrEqualReturnType cwiseLessOrEqual (const Scalar &s) const
 
template<int NaNPropagation = PropagateFast, typename OtherDerived>
constexpr const CwiseBinaryOp< internal::scalar_max_op< Scalar, Scalar, NaNPropagation >, const Derived, const OtherDerived > cwiseMax (const Eigen::SparseMatrixBase< OtherDerived > &other) const
 
template<int NaNPropagation = PropagateFast>
constexpr const CwiseBinaryOp< internal::scalar_max_op< Scalar, Scalar, NaNPropagation >, const Derived, const ConstantReturnType > cwiseMax (const Scalar &other) const
 
template<int NaNPropagation = PropagateFast, typename OtherDerived>
constexpr const CwiseBinaryOp< internal::scalar_min_op< Scalar, Scalar, NaNPropagation >, const Derived, const OtherDerived > cwiseMin (const Eigen::SparseMatrixBase< OtherDerived > &other) const
 
template<int NaNPropagation = PropagateFast>
constexpr const CwiseBinaryOp< internal::scalar_min_op< Scalar, Scalar, NaNPropagation >, const Derived, const ConstantReturnType > cwiseMin (const Scalar &other) const
 
template<typename OtherDerived>
constexpr const CwiseBinaryNotEqualReturnType< OtherDerived > cwiseNotEqual (const Eigen::SparseMatrixBase< OtherDerived > &other) const
 
constexpr const CwiseScalarNotEqualReturnType cwiseNotEqual (const Scalar &s) const
 
template<typename OtherDerived>
constexpr const CwiseBinaryOp< internal::scalar_product_op< Derived ::Scalar, OtherDerived ::Scalar >, const Derived, const OtherDerived > cwiseProduct (const Eigen::SparseMatrixBase< OtherDerived > &other) const
 
template<typename OtherDerived>
constexpr const CwiseBinaryOp< internal::scalar_quotient_op< Scalar >, const Derived, const OtherDerived > cwiseQuotient (const Eigen::SparseMatrixBase< OtherDerived > &other) const
 
const CwiseUnaryOp< internal::scalar_sign_op< Scalar >, const Derived > cwiseSign () const
 
const CwiseUnaryOp< internal::scalar_sqrt_op< Scalar >, const Derived > cwiseSqrt () const
 
const CwiseUnaryOp< internal::scalar_square_op< Scalar >, const Derived > cwiseSquare () const
 
const internal::eval< Derived >::type eval () const
 
template<int N>
constexpr FixedSegmentReturnType< N >::Type head (Index n=N)
 
template<int N>
constexpr ConstFixedSegmentReturnType< N >::Type head (Index n=N) const
 This is the const version of head<int>().
 
template<typename NType>
constexpr FixedSegmentReturnType<... >::Type head (NType n)
 
template<typename NType>
constexpr const ConstFixedSegmentReturnType<... >::Type head (NType n) const
 This is the const version of head(NType).
 
constexpr NonConstImagReturnType imag ()
 
constexpr const ImagReturnType imag () const
 
Index innerSize () const
 
constexpr InnerVectorReturnType innerVector (Index outer)
 
constexpr const ConstInnerVectorReturnType innerVector (Index outer) const
 
constexpr InnerVectorsReturnType innerVectors (Index outerStart, Index outerSize)
 
constexpr const ConstInnerVectorsReturnType innerVectors (Index outerStart, Index outerSize) const
 
bool isVector () const
 
template<int N>
constexpr NColsBlockXpr< N >::Type leftCols (Index n=N)
 
template<int N>
constexpr ConstNColsBlockXpr< N >::Type leftCols (Index n=N) const
 This is the const version of leftCols<int>().
 
template<typename NColsType>
constexpr NColsBlockXpr<... >::Type leftCols (NColsType n)
 
template<typename NColsType>
constexpr const ConstNColsBlockXpr<... >::Type leftCols (NColsType n) const
 This is the const version of leftCols(NColsType).
 
template<int N>
constexpr NColsBlockXpr< N >::Type middleCols (Index startCol, Index n=N)
 
template<int N>
constexpr ConstNColsBlockXpr< N >::Type middleCols (Index startCol, Index n=N) const
 This is the const version of middleCols<int>().
 
template<typename NColsType>
constexpr NColsBlockXpr<... >::Type middleCols (Index startCol, NColsType numCols)
 
template<typename NColsType>
constexpr const ConstNColsBlockXpr<... >::Type middleCols (Index startCol, NColsType numCols) const
 This is the const version of middleCols(Index,NColsType).
 
template<int N>
constexpr NRowsBlockXpr< N >::Type middleRows (Index startRow, Index n=N)
 
template<int N>
constexpr ConstNRowsBlockXpr< N >::Type middleRows (Index startRow, Index n=N) const
 This is the const version of middleRows<int>().
 
template<typename NRowsType>
constexpr NRowsBlockXpr<... >::Type middleRows (Index startRow, NRowsType n)
 
template<typename NRowsType>
constexpr const ConstNRowsBlockXpr<... >::Type middleRows (Index startRow, NRowsType n) const
 This is the const version of middleRows(Index,NRowsType).
 
template<typename OtherDerived>
constexpr const CwiseBinaryOp< internal::scalar_bitwise_and_op< Scalar >, const Derived, const OtherDerived > operator& (const Eigen::SparseMatrixBase< OtherDerived > &other) const
 
template<typename OtherDerived>
constexpr const CwiseBinaryOp< internal::scalar_boolean_and_op< Scalar >, const Derived, const OtherDerived > operator&& (const Eigen::SparseMatrixBase< OtherDerived > &other) const
 
template<typename OtherDerived>
const Product< Derived, OtherDerived, AliasFreeProduct > operator* (const SparseMatrixBase< OtherDerived > &other) const
 
template<typename OtherDerived>
const CwiseBinaryOp< internal::scalar_sum_op< Scalar, typename OtherDerived::Scalar >, const Derived, const OtherDerived > operator+ (const Eigen::SparseMatrixBase< OtherDerived > &other) const
 
constexpr const NegativeReturnType operator- () const
 
template<typename OtherDerived>
const CwiseBinaryOp< internal::scalar_difference_op< Scalar, typename OtherDerived::Scalar >, const Derived, const OtherDerived > operator- (const Eigen::SparseMatrixBase< OtherDerived > &other) const
 
template<typename OtherDerived>
constexpr const CwiseBinaryOp< internal::scalar_bitwise_xor_op< Scalar >, const Derived, const OtherDerived > operator^ (const Eigen::SparseMatrixBase< OtherDerived > &other) const
 
template<typename OtherDerived>
constexpr const CwiseBinaryOp< internal::scalar_bitwise_or_op< Scalar >, const Derived, const OtherDerived > operator| (const Eigen::SparseMatrixBase< OtherDerived > &other) const
 
template<typename OtherDerived>
constexpr const CwiseBinaryOp< internal::scalar_boolean_or_op< Scalar >, const Derived, const OtherDerived > operator|| (const Eigen::SparseMatrixBase< OtherDerived > &other) const
 
Index outerSize () const
 
const SparseView< Derived > pruned (const Scalar &reference=Scalar(0), const RealScalar &epsilon=NumTraits< Scalar >::dummy_precision()) const
 
constexpr NonConstRealReturnType real ()
 
constexpr RealReturnType real () const
 
template<int N>
constexpr NColsBlockXpr< N >::Type rightCols (Index n=N)
 
template<int N>
constexpr ConstNColsBlockXpr< N >::Type rightCols (Index n=N) const
 This is the const version of rightCols<int>().
 
template<typename NColsType>
constexpr NColsBlockXpr<... >::Type rightCols (NColsType n)
 
template<typename NColsType>
constexpr const ConstNColsBlockXpr<... >::Type rightCols (NColsType n) const
 This is the const version of rightCols(NColsType).
 
constexpr RowXpr row (Index i)
 
constexpr ConstRowXpr row (Index i) const
 This is the const version of row().
 
Index rows () const
 
template<int N>
constexpr FixedSegmentReturnType< N >::Type segment (Index start, Index n=N)
 
template<int N>
constexpr ConstFixedSegmentReturnType< N >::Type segment (Index start, Index n=N) const
 This is the const version of segment<int>(Index).
 
template<typename NType>
constexpr FixedSegmentReturnType<... >::Type segment (Index start, NType n)
 
template<typename NType>
constexpr const ConstFixedSegmentReturnType<... >::Type segment (Index start, NType n) const
 This is the const version of segment(Index,NType).
 
Index size () const
 
template<DirectionType Direction>
constexpr std::conditional_t< Direction==Vertical, ColXpr, RowXpr > subVector (Index i)
 
template<DirectionType Direction>
constexpr std::conditional_t< Direction==Vertical, ConstColXpr, ConstRowXpr > subVector (Index i) const
 
template<DirectionType Direction>
constexpr Index subVectors () const
 
template<int N>
constexpr FixedSegmentReturnType< N >::Type tail (Index n=N)
 
template<int N>
constexpr ConstFixedSegmentReturnType< N >::Type tail (Index n=N) const
 This is the const version of tail<int>().
 
template<typename NType>
constexpr FixedSegmentReturnType<... >::Type tail (NType n)
 
template<typename NType>
constexpr const ConstFixedSegmentReturnType<... >::Type tail (NType n) const
 This is the const version of tail(NType).
 
template<int CRows, int CCols>
constexpr FixedBlockXpr< CRows, CCols >::Type topLeftCorner ()
 
template<int CRows, int CCols>
constexpr const ConstFixedBlockXpr< CRows, CCols >::Type topLeftCorner () const
 This is the const version of topLeftCorner<int, int>().
 
template<int CRows, int CCols>
constexpr FixedBlockXpr< CRows, CCols >::Type topLeftCorner (Index cRows, Index cCols)
 
template<int CRows, int CCols>
constexpr const ConstFixedBlockXpr< CRows, CCols >::Type topLeftCorner (Index cRows, Index cCols) const
 This is the const version of topLeftCorner<int, int>(Index, Index).
 
template<typename NRowsType, typename NColsType>
constexpr FixedBlockXpr<...,... >::Type topLeftCorner (NRowsType cRows, NColsType cCols)
 
template<typename NRowsType, typename NColsType>
constexpr const ConstFixedBlockXpr<...,... >::Type topLeftCorner (NRowsType cRows, NColsType cCols) const
 This is the const version of topLeftCorner(Index, Index).
 
template<int CRows, int CCols>
constexpr FixedBlockXpr< CRows, CCols >::Type topRightCorner ()
 
template<int CRows, int CCols>
constexpr const ConstFixedBlockXpr< CRows, CCols >::Type topRightCorner () const
 This is the const version of topRightCorner<int, int>().
 
template<int CRows, int CCols>
constexpr FixedBlockXpr< CRows, CCols >::Type topRightCorner (Index cRows, Index cCols)
 
template<int CRows, int CCols>
constexpr const ConstFixedBlockXpr< CRows, CCols >::Type topRightCorner (Index cRows, Index cCols) const
 This is the const version of topRightCorner<int, int>(Index, Index).
 
template<typename NRowsType, typename NColsType>
constexpr FixedBlockXpr<...,... >::Type topRightCorner (NRowsType cRows, NColsType cCols)
 
template<typename NRowsType, typename NColsType>
constexpr const ConstFixedBlockXpr<...,... >::Type topRightCorner (NRowsType cRows, NColsType cCols) const
 This is the const version of topRightCorner(NRowsType, NColsType).
 
template<int N>
constexpr NRowsBlockXpr< N >::Type topRows (Index n=N)
 
template<int N>
constexpr ConstNRowsBlockXpr< N >::Type topRows (Index n=N) const
 This is the const version of topRows<int>().
 
template<typename NRowsType>
constexpr NRowsBlockXpr<... >::Type topRows (NRowsType n)
 
template<typename NRowsType>
constexpr const ConstNRowsBlockXpr<... >::Type topRows (NRowsType n) const
 This is the const version of topRows(NRowsType).
 
SparseSymmetricPermutationProduct< Derived, Upper|Lower > twistedBy (const PermutationMatrix< Dynamic, Dynamic, StorageIndex > &perm) const
 
template<typename CustomUnaryOp>
constexpr const CwiseUnaryOp< CustomUnaryOp, const Derived > unaryExpr (const CustomUnaryOp &func=CustomUnaryOp()) const
 Apply a unary operator coefficient-wise.
 
template<typename CustomViewOp>
constexpr CwiseUnaryView< CustomViewOp, Derived > unaryViewExpr (const CustomViewOp &func=CustomViewOp())
 
template<typename CustomViewOp>
constexpr const CwiseUnaryView< CustomViewOp, const Derived > unaryViewExpr (const CustomViewOp &func=CustomViewOp()) const
 
- Public Member Functions inherited from Eigen::EigenBase< Derived >
constexpr Index cols () const noexcept
 
constexpr Derived & derived ()
 
constexpr const Derived & derived () const
 
constexpr Index rows () const noexcept
 
constexpr Index size () const noexcept
 

Member Typedef Documentation

◆ RealScalar

template<typename Derived>
using Eigen::SparseMatrixBase< Derived >::RealScalar

This is the "real scalar" type; if the Scalar type is already real numbers (e.g. int, float or double) then RealScalar is just the same as Scalar. If Scalar is std::complex<T> then RealScalar is T.

See also
class NumTraits

◆ StorageIndex

template<typename Derived>
using Eigen::SparseMatrixBase< Derived >::StorageIndex

The integer type used to store indices within a SparseMatrix. For a SparseMatrix<Scalar,Options,IndexType> it is an alias of the third template parameter IndexType.

◆ value_type

template<typename Derived>
using Eigen::SparseMatrixBase< Derived >::value_type

The numeric type of the expression's coefficients, e.g. float, double, int or std::complex<float>, etc.

It is an alias for the Scalar type

Member Enumeration Documentation

◆ anonymous enum

template<typename Derived>
anonymous enum
Enumerator
RowsAtCompileTime 

The number of rows at compile-time. This is just a copy of the value provided by the Derived type. If a value is not known at compile-time, it is set to the Dynamic constant.

See also
MatrixBase::rows(), MatrixBase::cols(), ColsAtCompileTime, SizeAtCompileTime
ColsAtCompileTime 

The number of columns at compile-time. This is just a copy of the value provided by the Derived type. If a value is not known at compile-time, it is set to the Dynamic constant.

See also
MatrixBase::rows(), MatrixBase::cols(), RowsAtCompileTime, SizeAtCompileTime
SizeAtCompileTime 

This is equal to the number of coefficients, i.e. the number of rows times the number of columns, or to Dynamic if this is not known at compile-time.

See also
RowsAtCompileTime, ColsAtCompileTime
IsVectorAtCompileTime 

This is set to true if either the number of rows or the number of columns is known at compile-time to be equal to 1. Indeed, in that case, we are dealing with a column-vector (if there is only one column) or with a row-vector (if there is only one row).

NumDimensions 

This value is equal to Tensor::NumDimensions, i.e. 0 for scalars, 1 for vectors, and 2 for matrices.

Flags 

This stores expression Flags flags which may or may not be inherited by new expressions constructed from this one. See the list of flags.

Member Function Documentation

◆ binaryExpr()

template<typename Derived>
template<typename CustomBinaryOp, typename OtherDerived>
const CwiseBinaryOp< CustomBinaryOp, const Derived, const OtherDerived > Eigen::SparseMatrixBase< Derived >::binaryExpr ( const Eigen::SparseMatrixBase< OtherDerived > & other,
const CustomBinaryOp & func = CustomBinaryOp() ) const
inlineconstexpr
Returns
an expression of a custom coefficient-wise operator func of *this and other

The template parameter CustomBinaryOp is the type of the functor of the custom operator (see class CwiseBinaryOp for an example)

Here is an example illustrating the use of custom functors:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
#include <Eigen/Core>
#include <iostream>
// define a custom template binary functor
template <typename Scalar>
struct MakeComplexOp {
typedef std::complex<Scalar> result_type;
result_type operator()(const Scalar& a, const Scalar& b) const { return result_type(a, b); }
};
int main(int, char**) {
Matrix4d m1 = Matrix4d::Random(), m2 = Matrix4d::Random();
std::cout << m1.binaryExpr(m2, MakeComplexOp<double>()) << std::endl;
return 0;
}
Matrix< double, 4, 4 > Matrix4d
4×4 matrix of type double.
Definition Matrix.h:489

Output:

(-0.211,-0.408)    (0.108,0.54)   (0.435,0.899)  (-0.198,-0.96)
 (0.597,0.0486)   (0.258,0.783)  (0.214,-0.828) (-0.782,-0.874)
 (-0.605,0.946) (0.0268,-0.295)  (-0.514,0.326)  (-0.563,0.941)
  (0.536,0.543)   (0.832,0.838)  (0.608,-0.302)   (0.678,0.702)
See also
class CwiseBinaryOp, operator+(), operator-(), cwiseProduct()

◆ block() [1/3]

template<typename Derived>
template<int NRows, int NCols>
FixedBlockXpr< NRows, NCols >::Type Eigen::SparseMatrixBase< Derived >::block ( Index startRow,
Index startCol )
inlineconstexpr
Returns
a fixed-size expression of a block of *this.

The template parameters NRows and NCols are the number of rows and columns in the block.

Parameters
startRowthe first row in the block
startColthe first column in the block

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
Matrix4i m = Matrix4i::Random();
cout << "Here is the matrix m:" << endl << m << endl;
cout << "Here is m.block<2,2>(1,1):" << endl << m.block<2, 2>(1, 1) << endl;
m.block<2, 2>(1, 1).setZero();
cout << "Now the matrix m is:" << endl << m << endl;
Matrix< int, 4, 4 > Matrix4i
4×4 matrix of type int.
Definition Matrix.h:487

Output:

Here is the matrix m:
 1804289383 -1550966999  -782303108   336465782
 -465790871 -1122281286 -1843394476   278722862
 1957747793 -1364114958    35005211  2145174067
-1427598262  -102585885 -1852781081 -1045969719
Here is m.block<2,2>(1,1):
-1122281286 -1843394476
-1364114958    35005211
Now the matrix m is:
 1804289383 -1550966999  -782303108   336465782
 -465790871           0           0   278722862
 1957747793           0           0  2145174067
-1427598262  -102585885 -1852781081 -1045969719
Note
The usage of this overload is discouraged from Eigen 3.4, better use the generic block(Index,Index,NRowsType,NColsType), here is the one-to-one equivalence:
mat.template block<NRows,NCols>(i,j) <--> mat.block(i,j,fix<NRows>,fix<NCols>)
constexpr FixedBlockXpr<...,... >::Type block(Index startRow, Index startCol, NRowsType blockRows, NColsType blockCols)
Definition SparseMatrixBase.h:123
static const auto fix()
since block is a templated member, the keyword template has to be used if the matrix type is also a template parameter:
m.template block<3,3>(1,1);
Warning
This method returns a read-only expression for any sparse matrices.
See also
Sparse block operations
block(Index,Index,NRowsType,NColsType), class Block

◆ block() [2/3]

template<typename Derived>
template<int NRows, int NCols>
FixedBlockXpr< NRows, NCols >::Type Eigen::SparseMatrixBase< Derived >::block ( Index startRow,
Index startCol,
Index blockRows,
Index blockCols )
inlineconstexpr
Returns
an expression of a block of *this.
Template Parameters
NRowsnumber of rows in block as specified at compile-time
NColsnumber of columns in block as specified at compile-time
Parameters
startRowthe first row in the block
startColthe first column in the block
blockRowsnumber of rows in block as specified at run-time
blockColsnumber of columns in block as specified at run-time

This function is mainly useful for blocks where the number of rows is specified at compile-time and the number of columns is specified at run-time, or vice versa. The compile-time and run-time information should not contradict. In other words, blockRows should equal NRows unless NRows is Dynamic, and the same for the number of columns.

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
Matrix4i m = Matrix4i::Random();
cout << "Here is the matrix m:" << endl << m << endl;
cout << "Here is the block:" << endl << m.block<2, Dynamic>(1, 1, 2, 3) << endl;
m.block<2, Dynamic>(1, 1, 2, 3).setZero();
cout << "Now the matrix m is:" << endl << m << endl;

Output:

Here is the matrix m:
 1804289383 -1550966999  -782303108   336465782
 -465790871 -1122281286 -1843394476   278722862
 1957747793 -1364114958    35005211  2145174067
-1427598262  -102585885 -1852781081 -1045969719
Here is the block:
-1122281286 -1843394476   278722862
-1364114958    35005211  2145174067
Now the matrix m is:
 1804289383 -1550966999  -782303108   336465782
 -465790871           0           0           0
 1957747793           0           0           0
-1427598262  -102585885 -1852781081 -1045969719
Note
The usage of this overload is discouraged from Eigen 3.4, better use the generic block(Index,Index,NRowsType,NColsType), here is the one-to-one complete equivalence:
mat.template block<NRows,NCols>(i,j,rows,cols) <--> mat.block(i,j,fix<NRows>(rows),fix<NCols>(cols))
Index rows() const
Definition SparseMatrixBase.h:182
Index cols() const
Definition SparseMatrixBase.h:184
If we known that, e.g., NRows==Dynamic and NCols!=Dynamic, then the equivalence becomes:
mat.template block<Dynamic,NCols>(i,j,rows,NCols) <--> mat.block(i,j,rows,fix<NCols>)
Warning
This method returns a read-only expression for any sparse matrices.
See also
Sparse block operations
block(Index,Index,NRowsType,NColsType), class Block

◆ block() [3/3]

template<typename Derived>
template<typename NRowsType, typename NColsType>
FixedBlockXpr<...,... >::Type Eigen::SparseMatrixBase< Derived >::block ( Index startRow,
Index startCol,
NRowsType blockRows,
NColsType blockCols )
inlineconstexpr
Returns
an expression of a block in *this with either dynamic or fixed sizes.
Parameters
startRowthe first row in the block
startColthe first column in the block
blockRowsnumber of rows in the block, specified at either run-time or compile-time
blockColsnumber of columns in the block, specified at either run-time or compile-time
Template Parameters
NRowsTypethe type of the value handling the number of rows in the block, typically Index.
NColsTypethe type of the value handling the number of columns in the block, typically Index.

Example using runtime (aka dynamic) sizes:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
Matrix4i m = Matrix4i::Random();
cout << "Here is the matrix m:" << endl << m << endl;
cout << "Here is m.block(1, 1, 2, 2):" << endl << m.block(1, 1, 2, 2) << endl;
m.block(1, 1, 2, 2).setZero();
cout << "Now the matrix m is:" << endl << m << endl;
Derived & setZero(Index size)
Definition CwiseNullaryOp.h:536

Output:

Here is the matrix m:
 1804289383 -1550966999  -782303108   336465782
 -465790871 -1122281286 -1843394476   278722862
 1957747793 -1364114958    35005211  2145174067
-1427598262  -102585885 -1852781081 -1045969719
Here is m.block(1, 1, 2, 2):
-1122281286 -1843394476
-1364114958    35005211
Now the matrix m is:
 1804289383 -1550966999  -782303108   336465782
 -465790871           0           0   278722862
 1957747793           0           0  2145174067
-1427598262  -102585885 -1852781081 -1045969719

New in Eigen 3.4.:

The number of rows blockRows and columns blockCols can also be specified at compile-time by passing Eigen::fix<N>, or Eigen::fix<N>(n) as arguments. In the later case, n plays the role of a runtime fallback value in case N equals Eigen::Dynamic. Here is an example with a fixed number of rows NRows and dynamic number of columns cols:

mat.block(i,j,fix<NRows>,cols)

This function thus fully covers the features offered by the following overloads block<NRows,NCols>(Index, Index), and block<NRows,NCols>(Index, Index, Index, Index) that are thus obsolete. Indeed, this generic version avoids redundancy, it preserves the argument order, and prevents the need to rely on the template keyword in templated code.

but with less redundancy and more consistency as it does not modify the argument order and seamlessly enable hybrid fixed/dynamic sizes.

Note
Even in the case that the returned expression has dynamic size, in the case when it is applied to a fixed-size matrix, it inherits a fixed maximal size, which means that evaluating it does not cause a dynamic memory allocation.
Warning
This method returns a read-only expression for any sparse matrices.
See also
Sparse block operations
class Block, fix, fix<N>(int)

◆ bottomLeftCorner() [1/3]

template<typename Derived>
template<int CRows, int CCols>
FixedBlockXpr< CRows, CCols >::Type Eigen::SparseMatrixBase< Derived >::bottomLeftCorner ( )
inlineconstexpr
Returns
an expression of a fixed-size bottom-left corner of *this.

The template parameters CRows and CCols are the number of rows and columns in the corner.

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
Matrix4i m = Matrix4i::Random();
cout << "Here is the matrix m:" << endl << m << endl;
cout << "Here is m.bottomLeftCorner<2,2>():" << endl;
cout << m.bottomLeftCorner<2, 2>() << endl;
m.bottomLeftCorner<2, 2>().setZero();
cout << "Now the matrix m is:" << endl << m << endl;

Output:

Here is the matrix m:
 1804289383 -1550966999  -782303108   336465782
 -465790871 -1122281286 -1843394476   278722862
 1957747793 -1364114958    35005211  2145174067
-1427598262  -102585885 -1852781081 -1045969719
Here is m.bottomLeftCorner<2,2>():
 1957747793 -1364114958
-1427598262  -102585885
Now the matrix m is:
 1804289383 -1550966999  -782303108   336465782
 -465790871 -1122281286 -1843394476   278722862
          0           0    35005211  2145174067
          0           0 -1852781081 -1045969719
Warning
This method returns a read-only expression for any sparse matrices.
See also
Sparse block operations
block(Index,Index,NRowsType,NColsType), class Block

◆ bottomLeftCorner() [2/3]

template<typename Derived>
template<int CRows, int CCols>
FixedBlockXpr< CRows, CCols >::Type Eigen::SparseMatrixBase< Derived >::bottomLeftCorner ( Index cRows,
Index cCols )
inline
Returns
an expression of a bottom-left corner of *this.
Template Parameters
CRowsnumber of rows in corner as specified at compile-time
CColsnumber of columns in corner as specified at compile-time
Parameters
cRowsnumber of rows in corner as specified at run-time
cColsnumber of columns in corner as specified at run-time

This function is mainly useful for corners where the number of rows is specified at compile-time and the number of columns is specified at run-time, or vice versa. The compile-time and run-time information should not contradict. In other words, cRows should equal CRows unless CRows is Dynamic, and the same for the number of columns.

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
Matrix4i m = Matrix4i::Random();
cout << "Here is the matrix m:" << endl << m << endl;
cout << "Here is m.bottomLeftCorner<2,Dynamic>(2,2):" << endl;
cout << m.bottomLeftCorner<2, Dynamic>(2, 2) << endl;
m.bottomLeftCorner<2, Dynamic>(2, 2).setZero();
cout << "Now the matrix m is:" << endl << m << endl;

Output:

Here is the matrix m:
 1804289383 -1550966999  -782303108   336465782
 -465790871 -1122281286 -1843394476   278722862
 1957747793 -1364114958    35005211  2145174067
-1427598262  -102585885 -1852781081 -1045969719
Here is m.bottomLeftCorner<2,Dynamic>(2,2):
 1957747793 -1364114958
-1427598262  -102585885
Now the matrix m is:
 1804289383 -1550966999  -782303108   336465782
 -465790871 -1122281286 -1843394476   278722862
          0           0    35005211  2145174067
          0           0 -1852781081 -1045969719
Warning
This method returns a read-only expression for any sparse matrices.
See also
Sparse block operations
class Block

◆ bottomLeftCorner() [3/3]

template<typename Derived>
template<typename NRowsType, typename NColsType>
FixedBlockXpr<...,... >::Type Eigen::SparseMatrixBase< Derived >::bottomLeftCorner ( NRowsType cRows,
NColsType cCols )
inlineconstexpr
Returns
an expression of a bottom-left corner of *this with either dynamic or fixed sizes.
Parameters
cRowsthe number of rows in the corner
cColsthe number of columns in the corner
Template Parameters
NRowsTypethe type of the value handling the number of rows in the block, typically Index.
NColsTypethe type of the value handling the number of columns in the block, typically Index.

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
Matrix4i m = Matrix4i::Random();
cout << "Here is the matrix m:" << endl << m << endl;
cout << "Here is m.bottomLeftCorner(2, 2):" << endl;
cout << m.bottomLeftCorner(2, 2) << endl;
m.bottomLeftCorner(2, 2).setZero();
cout << "Now the matrix m is:" << endl << m << endl;

Output:

Here is the matrix m:
 1804289383 -1550966999  -782303108   336465782
 -465790871 -1122281286 -1843394476   278722862
 1957747793 -1364114958    35005211  2145174067
-1427598262  -102585885 -1852781081 -1045969719
Here is m.bottomLeftCorner(2, 2):
 1957747793 -1364114958
-1427598262  -102585885
Now the matrix m is:
 1804289383 -1550966999  -782303108   336465782
 -465790871 -1122281286 -1843394476   278722862
          0           0    35005211  2145174067
          0           0 -1852781081 -1045969719

The number of rows blockRows and columns blockCols can also be specified at compile-time by passing Eigen::fix<N>, or Eigen::fix<N>(n) as arguments. See block() for the details.

Warning
This method returns a read-only expression for any sparse matrices.
See also
Sparse block operations
block(Index,Index,NRowsType,NColsType), class Block

◆ bottomRightCorner() [1/3]

template<typename Derived>
template<int CRows, int CCols>
FixedBlockXpr< CRows, CCols >::Type Eigen::SparseMatrixBase< Derived >::bottomRightCorner ( )
inlineconstexpr
Returns
an expression of a fixed-size bottom-right corner of *this.

The template parameters CRows and CCols are the number of rows and columns in the corner.

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
Matrix4i m = Matrix4i::Random();
cout << "Here is the matrix m:" << endl << m << endl;
cout << "Here is m.bottomRightCorner<2,2>():" << endl;
cout << m.bottomRightCorner<2, 2>() << endl;
m.bottomRightCorner<2, 2>().setZero();
cout << "Now the matrix m is:" << endl << m << endl;

Output:

Here is the matrix m:
 1804289383 -1550966999  -782303108   336465782
 -465790871 -1122281286 -1843394476   278722862
 1957747793 -1364114958    35005211  2145174067
-1427598262  -102585885 -1852781081 -1045969719
Here is m.bottomRightCorner<2,2>():
   35005211  2145174067
-1852781081 -1045969719
Now the matrix m is:
 1804289383 -1550966999  -782303108   336465782
 -465790871 -1122281286 -1843394476   278722862
 1957747793 -1364114958           0           0
-1427598262  -102585885           0           0
Warning
This method returns a read-only expression for any sparse matrices.
See also
Sparse block operations
block(Index,Index,NRowsType,NColsType), class Block

◆ bottomRightCorner() [2/3]

template<typename Derived>
template<int CRows, int CCols>
FixedBlockXpr< CRows, CCols >::Type Eigen::SparseMatrixBase< Derived >::bottomRightCorner ( Index cRows,
Index cCols )
inlineconstexpr
Returns
an expression of a bottom-right corner of *this.
Template Parameters
CRowsnumber of rows in corner as specified at compile-time
CColsnumber of columns in corner as specified at compile-time
Parameters
cRowsnumber of rows in corner as specified at run-time
cColsnumber of columns in corner as specified at run-time

This function is mainly useful for corners where the number of rows is specified at compile-time and the number of columns is specified at run-time, or vice versa. The compile-time and run-time information should not contradict. In other words, cRows should equal CRows unless CRows is Dynamic, and the same for the number of columns.

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
Matrix4i m = Matrix4i::Random();
cout << "Here is the matrix m:" << endl << m << endl;
cout << "Here is m.bottomRightCorner<2,Dynamic>(2,2):" << endl;
cout << m.bottomRightCorner<2, Dynamic>(2, 2) << endl;
m.bottomRightCorner<2, Dynamic>(2, 2).setZero();
cout << "Now the matrix m is:" << endl << m << endl;

Output:

Here is the matrix m:
 1804289383 -1550966999  -782303108   336465782
 -465790871 -1122281286 -1843394476   278722862
 1957747793 -1364114958    35005211  2145174067
-1427598262  -102585885 -1852781081 -1045969719
Here is m.bottomRightCorner<2,Dynamic>(2,2):
   35005211  2145174067
-1852781081 -1045969719
Now the matrix m is:
 1804289383 -1550966999  -782303108   336465782
 -465790871 -1122281286 -1843394476   278722862
 1957747793 -1364114958           0           0
-1427598262  -102585885           0           0
Warning
This method returns a read-only expression for any sparse matrices.
See also
Sparse block operations
class Block

◆ bottomRightCorner() [3/3]

template<typename Derived>
template<typename NRowsType, typename NColsType>
FixedBlockXpr<...,... >::Type Eigen::SparseMatrixBase< Derived >::bottomRightCorner ( NRowsType cRows,
NColsType cCols )
inlineconstexpr
Returns
an expression of a bottom-right corner of *this with either dynamic or fixed sizes.
Parameters
cRowsthe number of rows in the corner
cColsthe number of columns in the corner
Template Parameters
NRowsTypethe type of the value handling the number of rows in the block, typically Index.
NColsTypethe type of the value handling the number of columns in the block, typically Index.

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
Matrix4i m = Matrix4i::Random();
cout << "Here is the matrix m:" << endl << m << endl;
cout << "Here is m.bottomRightCorner(2, 2):" << endl;
cout << m.bottomRightCorner(2, 2) << endl;
m.bottomRightCorner(2, 2).setZero();
cout << "Now the matrix m is:" << endl << m << endl;

Output:

Here is the matrix m:
 1804289383 -1550966999  -782303108   336465782
 -465790871 -1122281286 -1843394476   278722862
 1957747793 -1364114958    35005211  2145174067
-1427598262  -102585885 -1852781081 -1045969719
Here is m.bottomRightCorner(2, 2):
   35005211  2145174067
-1852781081 -1045969719
Now the matrix m is:
 1804289383 -1550966999  -782303108   336465782
 -465790871 -1122281286 -1843394476   278722862
 1957747793 -1364114958           0           0
-1427598262  -102585885           0           0

The number of rows blockRows and columns blockCols can also be specified at compile-time by passing Eigen::fix<N>, or Eigen::fix<N>(n) as arguments. See block() for the details.

Warning
This method returns a read-only expression for any sparse matrices.
See also
Sparse block operations
block(Index,Index,NRowsType,NColsType), class Block

◆ bottomRows() [1/2]

template<typename Derived>
template<int N>
NRowsBlockXpr< N >::Type Eigen::SparseMatrixBase< Derived >::bottomRows ( Index n = N)
inlineconstexpr
Returns
a block consisting of the bottom rows of *this.
Template Parameters
Nthe number of rows in the block as specified at compile-time
Parameters
nthe number of rows in the block as specified at run-time

The compile-time and run-time information should not contradict. In other words, n should equal N unless N is Dynamic.

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
Array44i a = Array44i::Random();
cout << "Here is the array a:" << endl << a << endl;
cout << "Here is a.bottomRows<2>():" << endl;
cout << a.bottomRows<2>() << endl;
a.bottomRows<2>().setZero();
cout << "Now the array a is:" << endl << a << endl;

Output:

Here is the array a:
 1804289383 -1550966999  -782303108   336465782
 -465790871 -1122281286 -1843394476   278722862
 1957747793 -1364114958    35005211  2145174067
-1427598262  -102585885 -1852781081 -1045969719
Here is a.bottomRows<2>():
 1957747793 -1364114958    35005211  2145174067
-1427598262  -102585885 -1852781081 -1045969719
Now the array a is:
 1804289383 -1550966999  -782303108   336465782
 -465790871 -1122281286 -1843394476   278722862
          0           0           0           0
          0           0           0           0
Warning
This method returns a read-write expression for row - major sparse matrices only. Otherwise, the returned expression is read-only.
See also
Sparse block operations
block(Index,Index,NRowsType,NColsType), class Block

◆ bottomRows() [2/2]

template<typename Derived>
template<typename NRowsType>
NRowsBlockXpr<... >::Type Eigen::SparseMatrixBase< Derived >::bottomRows ( NRowsType n)
inlineconstexpr
Returns
a block consisting of the bottom rows of *this.
Parameters
nthe number of rows in the block
Template Parameters
NRowsTypethe type of the value handling the number of rows in the block, typically Index.

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
Array44i a = Array44i::Random();
cout << "Here is the array a:" << endl << a << endl;
cout << "Here is a.bottomRows(2):" << endl;
cout << a.bottomRows(2) << endl;
a.bottomRows(2).setZero();
cout << "Now the array a is:" << endl << a << endl;

Output:

Here is the array a:
 1804289383 -1550966999  -782303108   336465782
 -465790871 -1122281286 -1843394476   278722862
 1957747793 -1364114958    35005211  2145174067
-1427598262  -102585885 -1852781081 -1045969719
Here is a.bottomRows(2):
 1957747793 -1364114958    35005211  2145174067
-1427598262  -102585885 -1852781081 -1045969719
Now the array a is:
 1804289383 -1550966999  -782303108   336465782
 -465790871 -1122281286 -1843394476   278722862
          0           0           0           0
          0           0           0           0

The number of rows n can also be specified at compile-time by passing Eigen::fix<N>, or Eigen::fix<N>(n) as arguments. See block() for the details.

Warning
This method returns a read-write expression for row - major sparse matrices only. Otherwise, the returned expression is read-only.
See also
Sparse block operations
block(Index,Index,NRowsType,NColsType), class Block

◆ cast()

template<typename Derived>
template<typename NewType>
CastXpr< NewType >::Type Eigen::SparseMatrixBase< Derived >::cast ( ) const
inlineconstexpr
Returns
an expression of *this with the Scalar type casted to NewScalar.

The template parameter NewScalar is the type we are casting the scalars to.

This method does not change the sparsity of *this: the conversion function is applied to explicitly stored coefficients only.

See also
SparseCompressedBase::coeffs()
class CwiseUnaryOp

◆ col()

template<typename Derived>
ColXpr Eigen::SparseMatrixBase< Derived >::col ( Index i)
inlineconstexpr
Returns
an expression of the i-th column of *this. Note that the numbering starts at 0.

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
Matrix3d m = Matrix3d::Identity();
m.col(1) = Vector3d(4, 5, 6);
cout << m << endl;
Matrix< double, 3, 1 > Vector3d
3×1 vector of type double.
Definition Matrix.h:489
Matrix< double, 3, 3 > Matrix3d
3×3 matrix of type double.
Definition Matrix.h:489

Output:

1 4 0
0 5 0
0 6 1
Warning
This method returns a read-write expression for column - major sparse matrices only. Otherwise, the returned expression is read-only.
See also
Sparse block operations
row(), class Block

◆ cols()

template<typename Derived>
Index Eigen::SparseMatrixBase< Derived >::cols ( ) const
inline
Returns
the number of columns.
See also
rows()

◆ conjugate()

template<typename Derived>
ConjugateReturnType Eigen::SparseMatrixBase< Derived >::conjugate ( ) const
inlineconstexpr
Returns
an expression of the complex conjugate of *this.

This method does not change the sparsity of *this: the complex conjugate is applied to explicitly stored coefficients only.

See also
SparseCompressedBase::coeffs()
Math functions, MatrixBase::adjoint()

◆ conjugateIf()

template<typename Derived>
template<bool Cond>
std::conditional_t< Cond, ConjugateReturnType, const Derived & > Eigen::SparseMatrixBase< Derived >::conjugateIf ( ) const
inlineconstexpr
Returns
an expression of the complex conjugate of *this if Cond==true, returns derived() otherwise.

This method does not change the sparsity of *this: the complex conjugate is applied to explicitly stored coefficients only.

See also
SparseCompressedBase::coeffs()
conjugate()

◆ cwiseAbs()

template<typename Derived>
const CwiseUnaryOp< internal::scalar_abs_op< Scalar >, const Derived > Eigen::SparseMatrixBase< Derived >::cwiseAbs ( ) const
Returns
an expression of the coefficient-wise absolute value of *this

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
MatrixXd m(2, 3);
m << 2, -4, 6, -5, 1, 0;
cout << m.cwiseAbs() << endl;
Matrix< double, Dynamic, Dynamic > MatrixXd
Dynamic×Dynamic matrix of type double.
Definition Matrix.h:489

Output:

2 4 6
5 1 0

This method does not change the sparsity of *this: the absolute value is applied to explicitly stored coefficients only.

See also
SparseCompressedBase::coeffs()
cwiseAbs2()

◆ cwiseAbs2()

template<typename Derived>
const CwiseUnaryOp< internal::scalar_abs2_op< Scalar >, const Derived > Eigen::SparseMatrixBase< Derived >::cwiseAbs2 ( ) const
Returns
an expression of the coefficient-wise squared absolute value of *this

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
MatrixXd m(2, 3);
m << 2, -4, 6, -5, 1, 0;
cout << m.cwiseAbs2() << endl;

Output:

 4 16 36
25  1  0

This method does not change the sparsity of *this: the squared absolute value is applied to explicitly stored coefficients only.

See also
SparseCompressedBase::coeffs()
cwiseAbs()

◆ cwiseArg()

template<typename Derived>
const CwiseUnaryOp< internal::scalar_arg_op< Scalar >, const Derived > Eigen::SparseMatrixBase< Derived >::cwiseArg ( ) const
Returns
an expression of the coefficient-wise phase angle of *this

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
MatrixXcf v = MatrixXcf::Random(2, 3);
cout << v << endl << endl;
cout << v.cwiseArg() << endl;
Matrix< std::complex< float >, Dynamic, Dynamic > MatrixXcf
Dynamic×Dynamic matrix of type std::complex<float>.
Definition Matrix.h:490

Output:

  (0.68,-0.211)  (0.823,-0.605)  (-0.444,0.108)
  (0.566,0.597)   (-0.33,0.536) (-0.0452,0.258)

-0.301 -0.634    2.9
 0.812   2.12   1.74

This method does not change the sparsity of *this: the arg is applied to explicitly stored coefficients only.

See also
SparseCompressedBase::coeffs()

◆ cwiseCbrt()

template<typename Derived>
const CwiseUnaryOp< internal::scalar_cbrt_op< Scalar >, const Derived > Eigen::SparseMatrixBase< Derived >::cwiseCbrt ( ) const
Returns
an expression of the coefficient-wise cube root of *this.

This method does not change the sparsity of *this: the cube - root is applied to explicitly stored coefficients only.

See also
SparseCompressedBase::coeffs()
cwiseSqrt(), cwiseSquare(), cwisePow()

◆ cwiseEqual() [1/2]

template<typename Derived>
template<typename OtherDerived>
const CwiseBinaryEqualReturnType< OtherDerived > Eigen::SparseMatrixBase< Derived >::cwiseEqual ( const Eigen::SparseMatrixBase< OtherDerived > & other) const
inlineconstexpr
Returns
an expression of the coefficient-wise == operator of *this and other
Warning
this performs an exact comparison, which is generally a bad idea with floating-point types. In order to check for equality between two vectors or matrices with floating-point coefficients, it is generally a far better idea to use a fuzzy comparison as provided by isApprox() and isMuchSmallerThan().

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
MatrixXi m(2, 2);
m << 1, 0, 1, 1;
cout << "Comparing m with identity matrix:" << endl;
cout << m.cwiseEqual(MatrixXi::Identity(2, 2)) << endl;
Index count = m.cwiseEqual(MatrixXi::Identity(2, 2)).count();
cout << "Number of coefficients that are equal: " << count << endl;
Matrix< int, Dynamic, Dynamic > MatrixXi
Dynamic×Dynamic matrix of type int.
Definition Matrix.h:487
Eigen::Index Index
The interface type of indices.
Definition EigenBase.h:44

Output:

Comparing m with identity matrix:
1 1
0 1
Number of coefficients that are equal: 3
See also
cwiseNotEqual(), isApprox(), isMuchSmallerThan()

◆ cwiseEqual() [2/2]

template<typename Derived>
const CwiseScalarEqualReturnType Eigen::SparseMatrixBase< Derived >::cwiseEqual ( const Scalar & s) const
inlineconstexpr
Returns
an expression of the coefficient-wise == operator of *this and a scalar s
Warning
this performs an exact comparison, which is generally a bad idea with floating-point types. In order to check for equality between two vectors or matrices with floating-point coefficients, it is generally a far better idea to use a fuzzy comparison as provided by isApprox() and isMuchSmallerThan().
See also
cwiseEqual(const MatrixBase<OtherDerived> &) const

◆ cwiseGreater() [1/2]

template<typename Derived>
template<typename OtherDerived>
const CwiseBinaryGreaterReturnType< OtherDerived > Eigen::SparseMatrixBase< Derived >::cwiseGreater ( const Eigen::SparseMatrixBase< OtherDerived > & other) const
inlineconstexpr
Returns
an expression of the coefficient-wise > operator of *this and other

◆ cwiseGreater() [2/2]

template<typename Derived>
const CwiseScalarGreaterReturnType Eigen::SparseMatrixBase< Derived >::cwiseGreater ( const Scalar & s) const
inlineconstexpr
Returns
an expression of the coefficient-wise > operator of *this and a scalar s

◆ cwiseGreaterOrEqual() [1/2]

template<typename Derived>
template<typename OtherDerived>
const CwiseBinaryGreaterOrEqualReturnType< OtherDerived > Eigen::SparseMatrixBase< Derived >::cwiseGreaterOrEqual ( const Eigen::SparseMatrixBase< OtherDerived > & other) const
inlineconstexpr
Returns
an expression of the coefficient-wise >= operator of *this and other

◆ cwiseGreaterOrEqual() [2/2]

template<typename Derived>
const CwiseScalarGreaterOrEqualReturnType Eigen::SparseMatrixBase< Derived >::cwiseGreaterOrEqual ( const Scalar & s) const
inlineconstexpr
Returns
an expression of the coefficient-wise >= operator of *this and a scalar s

◆ cwiseInverse()

template<typename Derived>
const CwiseUnaryOp< internal::scalar_inverse_op< Scalar >, const Derived > Eigen::SparseMatrixBase< Derived >::cwiseInverse ( ) const
Returns
an expression of the coefficient-wise inverse of *this.

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
MatrixXd m(2, 3);
m << 2, 0.5, 1, 3, 0.25, 1;
cout << m.cwiseInverse() << endl;

Output:

  0.5     2     1
0.333     4     1

This method does not change the sparsity of *this: the inverse is applied to explicitly stored coefficients only.

See also
SparseCompressedBase::coeffs()
cwiseProduct()

◆ cwiseLess() [1/2]

template<typename Derived>
template<typename OtherDerived>
const CwiseBinaryLessReturnType< OtherDerived > Eigen::SparseMatrixBase< Derived >::cwiseLess ( const Eigen::SparseMatrixBase< OtherDerived > & other) const
inlineconstexpr
Returns
an expression of the coefficient-wise < operator of *this and other

◆ cwiseLess() [2/2]

template<typename Derived>
const CwiseScalarLessReturnType Eigen::SparseMatrixBase< Derived >::cwiseLess ( const Scalar & s) const
inlineconstexpr
Returns
an expression of the coefficient-wise < operator of *this and a scalar s

◆ cwiseLessOrEqual() [1/2]

template<typename Derived>
template<typename OtherDerived>
const CwiseBinaryLessOrEqualReturnType< OtherDerived > Eigen::SparseMatrixBase< Derived >::cwiseLessOrEqual ( const Eigen::SparseMatrixBase< OtherDerived > & other) const
inlineconstexpr
Returns
an expression of the coefficient-wise <= operator of *this and other

◆ cwiseLessOrEqual() [2/2]

template<typename Derived>
const CwiseScalarLessOrEqualReturnType Eigen::SparseMatrixBase< Derived >::cwiseLessOrEqual ( const Scalar & s) const
inlineconstexpr
Returns
an expression of the coefficient-wise <= operator of *this and a scalar s

◆ cwiseMax() [1/2]

template<typename Derived>
template<int NaNPropagation = PropagateFast, typename OtherDerived>
const CwiseBinaryOp< internal::scalar_max_op< Scalar, Scalar, NaNPropagation >, const Derived, const OtherDerived > Eigen::SparseMatrixBase< Derived >::cwiseMax ( const Eigen::SparseMatrixBase< OtherDerived > & other) const
inlineconstexpr
Returns
an expression of the coefficient-wise max of *this and other

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
Vector3d v(2, 3, 4), w(4, 2, 3);
cout << v.cwiseMax(w) << endl;

Output:

4
3
4
See also
class CwiseBinaryOp, min()

◆ cwiseMax() [2/2]

template<typename Derived>
template<int NaNPropagation = PropagateFast>
const CwiseBinaryOp< internal::scalar_max_op< Scalar, Scalar, NaNPropagation >, const Derived, const ConstantReturnType > Eigen::SparseMatrixBase< Derived >::cwiseMax ( const Scalar & other) const
inlineconstexpr
Returns
an expression of the coefficient-wise max of *this and scalar other
See also
class CwiseBinaryOp, min()

◆ cwiseMin() [1/2]

template<typename Derived>
template<int NaNPropagation = PropagateFast, typename OtherDerived>
const CwiseBinaryOp< internal::scalar_min_op< Scalar, Scalar, NaNPropagation >, const Derived, const OtherDerived > Eigen::SparseMatrixBase< Derived >::cwiseMin ( const Eigen::SparseMatrixBase< OtherDerived > & other) const
inlineconstexpr
Returns
an expression of the coefficient-wise min of *this and other

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
Vector3d v(2, 3, 4), w(4, 2, 3);
cout << v.cwiseMin(w) << endl;

Output:

2
2
3
See also
class CwiseBinaryOp, max()

◆ cwiseMin() [2/2]

template<typename Derived>
template<int NaNPropagation = PropagateFast>
const CwiseBinaryOp< internal::scalar_min_op< Scalar, Scalar, NaNPropagation >, const Derived, const ConstantReturnType > Eigen::SparseMatrixBase< Derived >::cwiseMin ( const Scalar & other) const
inlineconstexpr
Returns
an expression of the coefficient-wise min of *this and scalar other
See also
class CwiseBinaryOp, min()

◆ cwiseNotEqual() [1/2]

template<typename Derived>
template<typename OtherDerived>
const CwiseBinaryNotEqualReturnType< OtherDerived > Eigen::SparseMatrixBase< Derived >::cwiseNotEqual ( const Eigen::SparseMatrixBase< OtherDerived > & other) const
inlineconstexpr
Returns
an expression of the coefficient-wise != operator of *this and other
Warning
this performs an exact comparison, which is generally a bad idea with floating-point types. In order to check for equality between two vectors or matrices with floating-point coefficients, it is generally a far better idea to use a fuzzy comparison as provided by isApprox() and isMuchSmallerThan().

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
MatrixXi m(2, 2);
m << 1, 0, 1, 1;
cout << "Comparing m with identity matrix:" << endl;
cout << m.cwiseNotEqual(MatrixXi::Identity(2, 2)) << endl;
Index count = m.cwiseNotEqual(MatrixXi::Identity(2, 2)).count();
cout << "Number of coefficients that are not equal: " << count << endl;

Output:

Comparing m with identity matrix:
0 0
1 0
Number of coefficients that are not equal: 1
See also
cwiseEqual(), isApprox(), isMuchSmallerThan()

◆ cwiseNotEqual() [2/2]

template<typename Derived>
const CwiseScalarNotEqualReturnType Eigen::SparseMatrixBase< Derived >::cwiseNotEqual ( const Scalar & s) const
inlineconstexpr
Returns
an expression of the coefficient-wise == operator of *this and a scalar s
Warning
this performs an exact comparison, which is generally a bad idea with floating-point types. In order to check for equality between two vectors or matrices with floating-point coefficients, it is generally a far better idea to use a fuzzy comparison as provided by isApprox() and isMuchSmallerThan().
See also
cwiseEqual(const MatrixBase<OtherDerived> &) const

◆ cwiseProduct()

template<typename Derived>
template<typename OtherDerived>
const CwiseBinaryOp< internal::scalar_product_op< Derived ::Scalar, OtherDerived ::Scalar >, const Derived, const OtherDerived > Eigen::SparseMatrixBase< Derived >::cwiseProduct ( const Eigen::SparseMatrixBase< OtherDerived > & other) const
inlineconstexpr
Returns
an expression of the Schur product (coefficient wise product) of *this and other

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
Matrix3i a = Matrix3i::Random(), b = Matrix3i::Random();
Matrix3i c = a.cwiseProduct(b);
cout << "a:\n" << a << "\nb:\n" << b << "\nc:\n" << c << endl;
Matrix< int, 3, 3 > Matrix3i
3×3 matrix of type int.
Definition Matrix.h:487

Output:

a:
 1804289383 -1427598262 -1364114958
 -465790871 -1550966999  -102585885
 1957747793 -1122281286  -782303108
b:
-1843394476   336465782 -1045969719
   35005211   278722862  1315634022
-1852781081  2145174067  -778350579
c:
  247332300  1274064924  1451757314
 1178627603   752122462  1323254130
-1164727785  -343432946  -653408692
See also
class CwiseBinaryOp, cwiseAbs2

◆ cwiseQuotient()

template<typename Derived>
template<typename OtherDerived>
const CwiseBinaryOp< internal::scalar_quotient_op< Scalar >, const Derived, const OtherDerived > Eigen::SparseMatrixBase< Derived >::cwiseQuotient ( const Eigen::SparseMatrixBase< OtherDerived > & other) const
inlineconstexpr
Returns
an expression of the coefficient-wise quotient of *this and other

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
Vector3d v(2, 3, 4), w(4, 2, 3);
cout << v.cwiseQuotient(w) << endl;

Output:

 0.5
 1.5
1.33
See also
class CwiseBinaryOp, cwiseProduct(), cwiseInverse()

◆ cwiseSign()

template<typename Derived>
const CwiseUnaryOp< internal::scalar_sign_op< Scalar >, const Derived > Eigen::SparseMatrixBase< Derived >::cwiseSign ( ) const
Returns
an expression of the coefficient-wise signum of *this.

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
MatrixXd m(2, 3);
m << 2, -4, 6, -5, 1, 0;
cout << m.cwiseSign() << endl;

Output:

 1 -1  1
-1  1  0

This method does not change the sparsity of *this: the sign function is applied to explicitly stored coefficients only.

See also
SparseCompressedBase::coeffs()

◆ cwiseSqrt()

template<typename Derived>
const CwiseUnaryOp< internal::scalar_sqrt_op< Scalar >, const Derived > Eigen::SparseMatrixBase< Derived >::cwiseSqrt ( ) const
Returns
an expression of the coefficient-wise square root of *this.

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
Vector3d v(1, 2, 4);
cout << v.cwiseSqrt() << endl;

Output:

   1
1.41
   2

This method does not change the sparsity of *this: the square - root is applied to explicitly stored coefficients only.

See also
SparseCompressedBase::coeffs()
cwisePow(), cwiseSquare(), cwiseCbrt()

◆ cwiseSquare()

template<typename Derived>
const CwiseUnaryOp< internal::scalar_square_op< Scalar >, const Derived > Eigen::SparseMatrixBase< Derived >::cwiseSquare ( ) const
Returns
an expression of the coefficient-wise square of *this.

This method does not change the sparsity of *this: the square is applied to explicitly stored coefficients only.

See also
SparseCompressedBase::coeffs()
cwisePow(), cwiseSqrt(), cwiseCbrt()

◆ eval()

template<typename Derived>
const internal::eval< Derived >::type Eigen::SparseMatrixBase< Derived >::eval ( ) const
inline
Returns
the matrix or vector obtained by evaluating this expression.

Notice that in the case of a plain matrix or vector (not an expression) this function just returns a const reference, in order to avoid a useless copy.

◆ head() [1/2]

template<typename Derived>
template<int N>
FixedSegmentReturnType< N >::Type Eigen::SparseMatrixBase< Derived >::head ( Index n = N)
inlineconstexpr
Returns
a fixed-size expression of the first coefficients of *this.

This is only for vectors (either row-vectors or column-vectors), i.e. matrices which are known at compile-time to have either one row or one column.

Template Parameters
Nthe number of coefficients in the segment as specified at compile-time
Parameters
nthe number of coefficients in the segment as specified at run-time

The compile-time and run-time information should not contradict. In other words, n should equal N unless N is Dynamic.

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
RowVector4i v = RowVector4i::Random();
cout << "Here is the vector v:" << endl << v << endl;
cout << "Here is v.head(2):" << endl << v.head<2>() << endl;
v.head<2>().setZero();
cout << "Now the vector v is:" << endl << v << endl;
Matrix< int, 1, 4 > RowVector4i
1×4 vector of type int.
Definition Matrix.h:487

Output:

Here is the vector v:
 1804289383  -465790871  1957747793 -1427598262
Here is v.head(2):
1804289383 -465790871
Now the vector v is:
          0           0  1957747793 -1427598262
See also
head(NType), class Block

◆ head() [2/2]

template<typename Derived>
template<typename NType>
FixedSegmentReturnType<... >::Type Eigen::SparseMatrixBase< Derived >::head ( NType n)
inlineconstexpr
Returns
an expression of the first coefficients of *this with either dynamic or fixed sizes.

This is only for vectors (either row-vectors or column-vectors), i.e. matrices which are known at compile-time to have either one row or one column.

Parameters
nthe number of coefficients in the segment
Template Parameters
NTypethe type of the value handling the number of coefficients in the segment, typically Index.

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
RowVector4i v = RowVector4i::Random();
cout << "Here is the vector v:" << endl << v << endl;
cout << "Here is v.head(2):" << endl << v.head(2) << endl;
v.head(2).setZero();
cout << "Now the vector v is:" << endl << v << endl;

Output:

Here is the vector v:
 1804289383  -465790871  1957747793 -1427598262
Here is v.head(2):
1804289383 -465790871
Now the vector v is:
          0           0  1957747793 -1427598262

The number of coefficients n can also be specified at compile-time by passing Eigen::fix<N>, or Eigen::fix<N>(n) as arguments. See block() for the details.

Note
Even in the case that the returned expression has dynamic size, in the case when it is applied to a fixed-size vector, it inherits a fixed maximal size, which means that evaluating it does not cause a dynamic memory allocation.
See also
class Block, block(Index,Index)

◆ imag() [1/2]

template<typename Derived>
NonConstImagReturnType Eigen::SparseMatrixBase< Derived >::imag ( )
inlineconstexpr
Returns
a non const expression of the imaginary part of *this. For real-valued objects the imaginary part is identically zero and not writable; this then returns the same read-only zero expression as the const overload.

This method does not change the sparsity of *this: the imaginary part function is applied to explicitly stored coefficients only.

See also
SparseCompressedBase::coeffs()
real(), realView()

◆ imag() [2/2]

template<typename Derived>
const ImagReturnType Eigen::SparseMatrixBase< Derived >::imag ( ) const
inlineconstexpr
Returns
a read-only expression of the imaginary part of *this.

This method does not change the sparsity of *this: the imaginary part function is applied to explicitly stored coefficients only.

See also
SparseCompressedBase::coeffs()
real(), realView()

◆ innerSize()

template<typename Derived>
Index Eigen::SparseMatrixBase< Derived >::innerSize ( ) const
inline
Returns
the size of the inner dimension according to the storage order, i.e., the number of rows for a column major matrix, and the number of cols otherwise

◆ innerVector() [1/2]

template<typename Derived>
InnerVectorReturnType Eigen::SparseMatrixBase< Derived >::innerVector ( Index outer)
inlineconstexpr
Returns
the outer -th column (resp. row) of the matrix *this if *this is col-major (resp. row-major).

◆ innerVector() [2/2]

template<typename Derived>
const ConstInnerVectorReturnType Eigen::SparseMatrixBase< Derived >::innerVector ( Index outer) const
inlineconstexpr
Returns
the outer -th column (resp. row) of the matrix *this if *this is col-major (resp. row-major). Read-only.

◆ innerVectors() [1/2]

template<typename Derived>
InnerVectorsReturnType Eigen::SparseMatrixBase< Derived >::innerVectors ( Index outerStart,
Index outerSize )
inlineconstexpr
Returns
the outerSize consecutive columns (resp. rows) of the matrix *this starting at outerStart if *this is col-major (resp. row-major).

◆ innerVectors() [2/2]

template<typename Derived>
const ConstInnerVectorsReturnType Eigen::SparseMatrixBase< Derived >::innerVectors ( Index outerStart,
Index outerSize ) const
inlineconstexpr
Returns
the outerSize consecutive columns (resp. rows) of the matrix *this starting at outerStart if *this is col-major (resp. row-major). Read-only.

◆ isVector()

template<typename Derived>
bool Eigen::SparseMatrixBase< Derived >::isVector ( ) const
inline
Returns
true if either the number of rows or the number of columns is equal to 1. In other words, this function returns
rows()==1 || cols()==1
See also
rows(), cols(), IsVectorAtCompileTime.

◆ leftCols() [1/2]

template<typename Derived>
template<int N>
NColsBlockXpr< N >::Type Eigen::SparseMatrixBase< Derived >::leftCols ( Index n = N)
inlineconstexpr
Returns
a block consisting of the left columns of *this.
Template Parameters
Nthe number of columns in the block as specified at compile-time
Parameters
nthe number of columns in the block as specified at run-time

The compile-time and run-time information should not contradict. In other words, n should equal N unless N is Dynamic.

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
Array44i a = Array44i::Random();
cout << "Here is the array a:" << endl << a << endl;
cout << "Here is a.leftCols<2>():" << endl;
cout << a.leftCols<2>() << endl;
a.leftCols<2>().setZero();
cout << "Now the array a is:" << endl << a << endl;

Output:

Here is the array a:
 1804289383 -1550966999  -782303108   336465782
 -465790871 -1122281286 -1843394476   278722862
 1957747793 -1364114958    35005211  2145174067
-1427598262  -102585885 -1852781081 -1045969719
Here is a.leftCols<2>():
 1804289383 -1550966999
 -465790871 -1122281286
 1957747793 -1364114958
-1427598262  -102585885
Now the array a is:
          0           0  -782303108   336465782
          0           0 -1843394476   278722862
          0           0    35005211  2145174067
          0           0 -1852781081 -1045969719
Warning
This method returns a read-write expression for column - major sparse matrices only. Otherwise, the returned expression is read-only.
See also
Sparse block operations
block(Index,Index,NRowsType,NColsType), class Block

◆ leftCols() [2/2]

template<typename Derived>
template<typename NColsType>
NColsBlockXpr<... >::Type Eigen::SparseMatrixBase< Derived >::leftCols ( NColsType n)
inlineconstexpr
Returns
a block consisting of the left columns of *this.
Parameters
nthe number of columns in the block
Template Parameters
NColsTypethe type of the value handling the number of columns in the block, typically Index.

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
Array44i a = Array44i::Random();
cout << "Here is the array a:" << endl << a << endl;
cout << "Here is a.leftCols(2):" << endl;
cout << a.leftCols(2) << endl;
a.leftCols(2).setZero();
cout << "Now the array a is:" << endl << a << endl;

Output:

Here is the array a:
 1804289383 -1550966999  -782303108   336465782
 -465790871 -1122281286 -1843394476   278722862
 1957747793 -1364114958    35005211  2145174067
-1427598262  -102585885 -1852781081 -1045969719
Here is a.leftCols(2):
 1804289383 -1550966999
 -465790871 -1122281286
 1957747793 -1364114958
-1427598262  -102585885
Now the array a is:
          0           0  -782303108   336465782
          0           0 -1843394476   278722862
          0           0    35005211  2145174067
          0           0 -1852781081 -1045969719

The number of columns n can also be specified at compile-time by passing Eigen::fix<N>, or Eigen::fix<N>(n) as arguments. See block() for the details.

Warning
This method returns a read-write expression for column - major sparse matrices only. Otherwise, the returned expression is read-only.
See also
Sparse block operations
block(Index,Index,NRowsType,NColsType), class Block

◆ middleCols() [1/2]

template<typename Derived>
template<int N>
NColsBlockXpr< N >::Type Eigen::SparseMatrixBase< Derived >::middleCols ( Index startCol,
Index n = N )
inlineconstexpr
Returns
a block consisting of a range of columns of *this.
Template Parameters
Nthe number of columns in the block as specified at compile-time
Parameters
startColthe index of the first column in the block
nthe number of columns in the block as specified at run-time

The compile-time and run-time information should not contradict. In other words, n should equal N unless N is Dynamic.

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
#include <Eigen/Core>
#include <iostream>
int main() {
int const N = 5;
Eigen::MatrixXi A(N, N);
A.setRandom();
std::cout << "A =\n" << A << '\n' << std::endl;
std::cout << "A(:,1..3) =\n" << A.middleCols<3>(1) << std::endl;
return 0;
}

Output:

A =
 1804289383 -1122281286    35005211 -1045969719 -1016307419
 -465790871 -1364114958 -1852781081  1315634022 -1287999227
 1957747793  -102585885   336465782  -778350579   608413784
-1427598262  -782303108   278722862 -1087522255  -412908450
-1550966999 -1843394476  2145174067 -1519308637 -1997685333

A(:,1..3) =
-1122281286    35005211 -1045969719
-1364114958 -1852781081  1315634022
 -102585885   336465782  -778350579
 -782303108   278722862 -1087522255
-1843394476  2145174067 -1519308637
Warning
This method returns a read-write expression for column - major sparse matrices only. Otherwise, the returned expression is read-only.
See also
Sparse block operations
block(Index,Index,NRowsType,NColsType), class Block

◆ middleCols() [2/2]

template<typename Derived>
template<typename NColsType>
NColsBlockXpr<... >::Type Eigen::SparseMatrixBase< Derived >::middleCols ( Index startCol,
NColsType numCols )
inlineconstexpr
Returns
a block consisting of a range of columns of *this.
Parameters
startColthe index of the first column in the block
numColsthe number of columns in the block
Template Parameters
NColsTypethe type of the value handling the number of columns in the block, typically Index.

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
#include <Eigen/Core>
#include <iostream>
int main() {
int const N = 5;
Eigen::MatrixXi A(N, N);
A.setRandom();
std::cout << "A =\n" << A << '\n' << std::endl;
std::cout << "A(1..3,:) =\n" << A.middleCols(1, 3) << std::endl;
return 0;
}

Output:

A =
 1804289383 -1122281286    35005211 -1045969719 -1016307419
 -465790871 -1364114958 -1852781081  1315634022 -1287999227
 1957747793  -102585885   336465782  -778350579   608413784
-1427598262  -782303108   278722862 -1087522255  -412908450
-1550966999 -1843394476  2145174067 -1519308637 -1997685333

A(1..3,:) =
-1122281286    35005211 -1045969719
-1364114958 -1852781081  1315634022
 -102585885   336465782  -778350579
 -782303108   278722862 -1087522255
-1843394476  2145174067 -1519308637

The number of columns n can also be specified at compile-time by passing Eigen::fix<N>, or Eigen::fix<N>(n) as arguments. See block() for the details.

Warning
This method returns a read-write expression for column - major sparse matrices only. Otherwise, the returned expression is read-only.
See also
Sparse block operations
block(Index,Index,NRowsType,NColsType), class Block

◆ middleRows() [1/2]

template<typename Derived>
template<int N>
NRowsBlockXpr< N >::Type Eigen::SparseMatrixBase< Derived >::middleRows ( Index startRow,
Index n = N )
inlineconstexpr
Returns
a block consisting of a range of rows of *this.
Template Parameters
Nthe number of rows in the block as specified at compile-time
Parameters
startRowthe index of the first row in the block
nthe number of rows in the block as specified at run-time

The compile-time and run-time information should not contradict. In other words, n should equal N unless N is Dynamic.

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
#include <Eigen/Core>
#include <iostream>
int main() {
int const N = 5;
Eigen::MatrixXi A(N, N);
A.setRandom();
std::cout << "A =\n" << A << '\n' << std::endl;
std::cout << "A(1..3,:) =\n" << A.middleRows<3>(1) << std::endl;
return 0;
}

Output:

A =
 1804289383 -1122281286    35005211 -1045969719 -1016307419
 -465790871 -1364114958 -1852781081  1315634022 -1287999227
 1957747793  -102585885   336465782  -778350579   608413784
-1427598262  -782303108   278722862 -1087522255  -412908450
-1550966999 -1843394476  2145174067 -1519308637 -1997685333

A(1..3,:) =
 -465790871 -1364114958 -1852781081  1315634022 -1287999227
 1957747793  -102585885   336465782  -778350579   608413784
-1427598262  -782303108   278722862 -1087522255  -412908450
Warning
This method returns a read-write expression for row - major sparse matrices only. Otherwise, the returned expression is read-only.
See also
Sparse block operations
block(Index,Index,NRowsType,NColsType), class Block

◆ middleRows() [2/2]

template<typename Derived>
template<typename NRowsType>
NRowsBlockXpr<... >::Type Eigen::SparseMatrixBase< Derived >::middleRows ( Index startRow,
NRowsType n )
inlineconstexpr
Returns
a block consisting of a range of rows of *this.
Parameters
startRowthe index of the first row in the block
nthe number of rows in the block
Template Parameters
NRowsTypethe type of the value handling the number of rows in the block, typically Index.

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
#include <Eigen/Core>
#include <iostream>
int main() {
int const N = 5;
Eigen::MatrixXi A(N, N);
A.setRandom();
std::cout << "A =\n" << A << '\n' << std::endl;
std::cout << "A(2..3,:) =\n" << A.middleRows(2, 2) << std::endl;
return 0;
}

Output:

A =
 1804289383 -1122281286    35005211 -1045969719 -1016307419
 -465790871 -1364114958 -1852781081  1315634022 -1287999227
 1957747793  -102585885   336465782  -778350579   608413784
-1427598262  -782303108   278722862 -1087522255  -412908450
-1550966999 -1843394476  2145174067 -1519308637 -1997685333

A(2..3,:) =
 1957747793  -102585885   336465782  -778350579   608413784
-1427598262  -782303108   278722862 -1087522255  -412908450

The number of rows n can also be specified at compile-time by passing Eigen::fix<N>, or Eigen::fix<N>(n) as arguments. See block() for the details.

Warning
This method returns a read-write expression for row - major sparse matrices only. Otherwise, the returned expression is read-only.
See also
Sparse block operations
block(Index,Index,NRowsType,NColsType), class Block

◆ operator&()

template<typename Derived>
template<typename OtherDerived>
const CwiseBinaryOp< internal::scalar_bitwise_and_op< Scalar >, const Derived, const OtherDerived > Eigen::SparseMatrixBase< Derived >::operator& ( const Eigen::SparseMatrixBase< OtherDerived > & other) const
inlineconstexpr
Returns
an expression of the bitwise and operator of *this and other
See also
operator|(), operator^()

◆ operator&&()

template<typename Derived>
template<typename OtherDerived>
const CwiseBinaryOp< internal::scalar_boolean_and_op< Scalar >, const Derived, const OtherDerived > Eigen::SparseMatrixBase< Derived >::operator&& ( const Eigen::SparseMatrixBase< OtherDerived > & other) const
inlineconstexpr
Returns
an expression of *this scaled by the scalar factor scalar
Template Parameters
Tis the scalar type of scalar. It must be compatible with the scalar type of the given expression.
Returns
an expression of *this divided by the scalar value scalar
Template Parameters
Tis the scalar type of scalar. It must be compatible with the scalar type of the given expression.
Returns
an expression of the coefficient-wise boolean and operator of *this and other

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
Array3d v(-1, 2, 1), w(-3, 2, 3);
cout << ((v < w) && (v < 0)) << endl;

Output:

0
0
0
See also
operator||(), select()

◆ operator*()

template<typename Derived>
template<typename OtherDerived>
const Product< Derived, OtherDerived, AliasFreeProduct > Eigen::SparseMatrixBase< Derived >::operator* ( const SparseMatrixBase< OtherDerived > & other) const
inline
Returns
an expression of the product of two sparse matrices. By default a conservative product preserving the symbolic non zeros is performed. The automatic pruning of the small values can be achieved by calling the pruned() function in which case a totally different product algorithm is employed:
C = (A*B).pruned(); // suppress numerical zeros (exact)
C = (A*B).pruned(ref);
C = (A*B).pruned(ref,epsilon);
const SparseView< Derived > pruned(const Scalar &reference=Scalar(0), const RealScalar &epsilon=NumTraits< Scalar >::dummy_precision()) const
Definition SparseView.h:219
where ref is a meaningful non zero reference value.

◆ operator+()

template<typename Derived>
template<typename OtherDerived>
const CwiseBinaryOp< internal::scalar_sum_op< Scalar, typename OtherDerived::Scalar >, const Derived, const OtherDerived > Eigen::SparseMatrixBase< Derived >::operator+ ( const Eigen::SparseMatrixBase< OtherDerived > & other) const
Returns
an expression of the sum of *this and other
Note
If you want to add a given scalar to all coefficients, see Cwise::operator+().
See also
class CwiseBinaryOp, operator+=()

◆ operator-() [1/2]

template<typename Derived>
const NegativeReturnType Eigen::SparseMatrixBase< Derived >::operator- ( ) const
inlineconstexpr
Returns
an expression of the opposite of *this
Note
Unary minus is not supported for bool coefficients. Cast to a signed integer type first.

This method does not change the sparsity of *this: the opposite is applied to explicitly stored coefficients only.

See also
SparseCompressedBase::coeffs()

◆ operator-() [2/2]

template<typename Derived>
template<typename OtherDerived>
const CwiseBinaryOp< internal::scalar_difference_op< Scalar, typename OtherDerived::Scalar >, const Derived, const OtherDerived > Eigen::SparseMatrixBase< Derived >::operator- ( const Eigen::SparseMatrixBase< OtherDerived > & other) const
Returns
an expression of the difference of *this and other
Note
Subtraction is not supported for bool coefficients. Cast to a signed integer type first.
If you want to subtract a given scalar from all coefficients, see Cwise::operator-().
See also
class CwiseBinaryOp, operator-=()

◆ operator^()

template<typename Derived>
template<typename OtherDerived>
const CwiseBinaryOp< internal::scalar_bitwise_xor_op< Scalar >, const Derived, const OtherDerived > Eigen::SparseMatrixBase< Derived >::operator^ ( const Eigen::SparseMatrixBase< OtherDerived > & other) const
inlineconstexpr
Returns
an expression of the bitwise xor operator of *this and other
See also
operator&(), operator|()

◆ operator|()

template<typename Derived>
template<typename OtherDerived>
const CwiseBinaryOp< internal::scalar_bitwise_or_op< Scalar >, const Derived, const OtherDerived > Eigen::SparseMatrixBase< Derived >::operator| ( const Eigen::SparseMatrixBase< OtherDerived > & other) const
inlineconstexpr
Returns
an expression of the bitwise or operator of *this and other
See also
operator&(), operator^()

◆ operator||()

template<typename Derived>
template<typename OtherDerived>
const CwiseBinaryOp< internal::scalar_boolean_or_op< Scalar >, const Derived, const OtherDerived > Eigen::SparseMatrixBase< Derived >::operator|| ( const Eigen::SparseMatrixBase< OtherDerived > & other) const
inlineconstexpr
Returns
an expression of the coefficient-wise boolean or operator of *this and other

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
Array3d v(-1, 2, 1), w(-3, 2, 3);
cout << ((v < w) || (v < 0)) << endl;

Output:

1
0
1
See also
operator&&(), select()

◆ outerSize()

template<typename Derived>
Index Eigen::SparseMatrixBase< Derived >::outerSize ( ) const
inline
Returns
the size of the storage major dimension, i.e., the number of columns for a column major matrix, and the number of rows otherwise

◆ pruned()

template<typename Derived>
const SparseView< Derived > Eigen::SparseMatrixBase< Derived >::pruned ( const Scalar & reference = Scalar(0),
const RealScalar & epsilon = NumTraits<Scalar>::dummy_precision() ) const
inline
Returns
an expression of *this with values smaller than reference * epsilon removed.

This method is typically used in conjunction with the product of two sparse matrices to automatically prune the smallest values as follows:

C = (A*B).pruned(); // suppress numerical zeros (exact)
C = (A*B).pruned(ref);
C = (A*B).pruned(ref,epsilon);

where ref is a meaningful non zero reference value.

◆ real() [1/2]

template<typename Derived>
NonConstRealReturnType Eigen::SparseMatrixBase< Derived >::real ( )
inlineconstexpr
Returns
a non const expression of the real part of *this.

This method does not change the sparsity of *this: the real part function is applied to explicitly stored coefficients only.

See also
SparseCompressedBase::coeffs()
imag(), realView()

◆ real() [2/2]

template<typename Derived>
RealReturnType Eigen::SparseMatrixBase< Derived >::real ( ) const
inlineconstexpr
Returns
a read-only expression of the real part of *this.

This method does not change the sparsity of *this: the real part function is applied to explicitly stored coefficients only.

See also
SparseCompressedBase::coeffs()
imag(), realView()

◆ rightCols() [1/2]

template<typename Derived>
template<int N>
NColsBlockXpr< N >::Type Eigen::SparseMatrixBase< Derived >::rightCols ( Index n = N)
inlineconstexpr
Returns
a block consisting of the right columns of *this.
Template Parameters
Nthe number of columns in the block as specified at compile-time
Parameters
nthe number of columns in the block as specified at run-time

The compile-time and run-time information should not contradict. In other words, n should equal N unless N is Dynamic.

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
Array44i a = Array44i::Random();
cout << "Here is the array a:" << endl << a << endl;
cout << "Here is a.rightCols<2>():" << endl;
cout << a.rightCols<2>() << endl;
a.rightCols<2>().setZero();
cout << "Now the array a is:" << endl << a << endl;

Output:

Here is the array a:
 1804289383 -1550966999  -782303108   336465782
 -465790871 -1122281286 -1843394476   278722862
 1957747793 -1364114958    35005211  2145174067
-1427598262  -102585885 -1852781081 -1045969719
Here is a.rightCols<2>():
 -782303108   336465782
-1843394476   278722862
   35005211  2145174067
-1852781081 -1045969719
Now the array a is:
 1804289383 -1550966999           0           0
 -465790871 -1122281286           0           0
 1957747793 -1364114958           0           0
-1427598262  -102585885           0           0
Warning
This method returns a read-write expression for column - major sparse matrices only. Otherwise, the returned expression is read-only.
See also
Sparse block operations
block(Index,Index,NRowsType,NColsType), class Block

◆ rightCols() [2/2]

template<typename Derived>
template<typename NColsType>
NColsBlockXpr<... >::Type Eigen::SparseMatrixBase< Derived >::rightCols ( NColsType n)
inlineconstexpr
Returns
a block consisting of the right columns of *this.
Parameters
nthe number of columns in the block
Template Parameters
NColsTypethe type of the value handling the number of columns in the block, typically Index.

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
Array44i a = Array44i::Random();
cout << "Here is the array a:" << endl << a << endl;
cout << "Here is a.rightCols(2):" << endl;
cout << a.rightCols(2) << endl;
a.rightCols(2).setZero();
cout << "Now the array a is:" << endl << a << endl;

Output:

Here is the array a:
 1804289383 -1550966999  -782303108   336465782
 -465790871 -1122281286 -1843394476   278722862
 1957747793 -1364114958    35005211  2145174067
-1427598262  -102585885 -1852781081 -1045969719
Here is a.rightCols(2):
 -782303108   336465782
-1843394476   278722862
   35005211  2145174067
-1852781081 -1045969719
Now the array a is:
 1804289383 -1550966999           0           0
 -465790871 -1122281286           0           0
 1957747793 -1364114958           0           0
-1427598262  -102585885           0           0

The number of columns n can also be specified at compile-time by passing Eigen::fix<N>, or Eigen::fix<N>(n) as arguments. See block() for the details.

Warning
This method returns a read-write expression for column - major sparse matrices only. Otherwise, the returned expression is read-only.
See also
Sparse block operations
block(Index,Index,NRowsType,NColsType), class Block

◆ row()

template<typename Derived>
RowXpr Eigen::SparseMatrixBase< Derived >::row ( Index i)
inlineconstexpr
Returns
an expression of the i-th row of *this. Note that the numbering starts at 0.

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
Matrix3d m = Matrix3d::Identity();
m.row(1) = Vector3d(4, 5, 6);
cout << m << endl;

Output:

1 0 0
4 5 6
0 0 1
Warning
This method returns a read-write expression for row - major sparse matrices only. Otherwise, the returned expression is read-only.
See also
Sparse block operations
col(), class Block

◆ rows()

template<typename Derived>
Index Eigen::SparseMatrixBase< Derived >::rows ( ) const
inline
Returns
the number of rows.
See also
cols()

◆ segment() [1/2]

template<typename Derived>
template<int N>
FixedSegmentReturnType< N >::Type Eigen::SparseMatrixBase< Derived >::segment ( Index start,
Index n = N )
inlineconstexpr
Returns
a fixed-size expression of a segment (i.e. a vector block) in *this

This is only for vectors (either row-vectors or column-vectors), i.e. matrices which are known at compile-time to have either one row or one column.

Template Parameters
Nthe number of coefficients in the segment as specified at compile-time
Parameters
startthe index of the first element in the segment
nthe number of coefficients in the segment as specified at compile-time

The compile-time and run-time information should not contradict. In other words, n should equal N unless N is Dynamic.

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
RowVector4i v = RowVector4i::Random();
cout << "Here is the vector v:" << endl << v << endl;
cout << "Here is v.segment<2>(1):" << endl << v.segment<2>(1) << endl;
v.segment<2>(2).setZero();
cout << "Now the vector v is:" << endl << v << endl;

Output:

Here is the vector v:
 1804289383  -465790871  1957747793 -1427598262
Here is v.segment<2>(1):
-465790871 1957747793
Now the vector v is:
1804289383 -465790871          0          0
See also
segment(Index,NType), class Block

◆ segment() [2/2]

template<typename Derived>
template<typename NType>
FixedSegmentReturnType<... >::Type Eigen::SparseMatrixBase< Derived >::segment ( Index start,
NType n )
inlineconstexpr
Returns
an expression of a segment (i.e. a vector block) in *this with either dynamic or fixed sizes.

This is only for vectors (either row-vectors or column-vectors), i.e. matrices which are known at compile-time to have either one row or one column.

Parameters
startthe first coefficient in the segment
nthe number of coefficients in the segment
Template Parameters
NTypethe type of the value handling the number of coefficients in the segment, typically Index.

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
RowVector4i v = RowVector4i::Random();
cout << "Here is the vector v:" << endl << v << endl;
cout << "Here is v.segment(1, 2):" << endl << v.segment(1, 2) << endl;
v.segment(1, 2).setZero();
cout << "Now the vector v is:" << endl << v << endl;

Output:

Here is the vector v:
 1804289383  -465790871  1957747793 -1427598262
Here is v.segment(1, 2):
-465790871 1957747793
Now the vector v is:
 1804289383           0           0 -1427598262

The number of coefficients n can also be specified at compile-time by passing Eigen::fix<N>, or Eigen::fix<N>(n) as arguments. See block() for the details.

Note
Even in the case that the returned expression has dynamic size, in the case when it is applied to a fixed-size vector, it inherits a fixed maximal size, which means that evaluating it does not cause a dynamic memory allocation.
See also
block(Index,Index,NRowsType,NColsType), fix<N>, fix<N>(int), class Block

◆ size()

template<typename Derived>
Index Eigen::SparseMatrixBase< Derived >::size ( ) const
inline
Returns
the number of coefficients, which is rows()*cols().
See also
rows(), cols().

◆ subVector() [1/2]

template<typename Derived>
template<DirectionType Direction>
std::conditional_t< Direction==Vertical, ColXpr, RowXpr > Eigen::SparseMatrixBase< Derived >::subVector ( Index i)
inlineconstexpr
Returns
the i-th subvector (column or vector) according to the Direction
See also
subVectors()

◆ subVector() [2/2]

template<typename Derived>
template<DirectionType Direction>
std::conditional_t< Direction==Vertical, ConstColXpr, ConstRowXpr > Eigen::SparseMatrixBase< Derived >::subVector ( Index i) const
inlineconstexpr

This is the const version of subVector(Index)

◆ subVectors()

template<typename Derived>
template<DirectionType Direction>
Index Eigen::SparseMatrixBase< Derived >::subVectors ( ) const
inlineconstexpr
Returns
the number of subvectors (rows or columns) in the direction Direction
See also
subVector(Index)

◆ tail() [1/2]

template<typename Derived>
template<int N>
FixedSegmentReturnType< N >::Type Eigen::SparseMatrixBase< Derived >::tail ( Index n = N)
inlineconstexpr
Returns
a fixed-size expression of the last coefficients of *this.

This is only for vectors (either row-vectors or column-vectors), i.e. matrices which are known at compile-time to have either one row or one column.

Template Parameters
Nthe number of coefficients in the segment as specified at compile-time
Parameters
nthe number of coefficients in the segment as specified at run-time

The compile-time and run-time information should not contradict. In other words, n should equal N unless N is Dynamic.

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
RowVector4i v = RowVector4i::Random();
cout << "Here is the vector v:" << endl << v << endl;
cout << "Here is v.tail(2):" << endl << v.tail<2>() << endl;
v.tail<2>().setZero();
cout << "Now the vector v is:" << endl << v << endl;

Output:

Here is the vector v:
 1804289383  -465790871  1957747793 -1427598262
Here is v.tail(2):
 1957747793 -1427598262
Now the vector v is:
1804289383 -465790871          0          0
See also
tail(NType), class Block

◆ tail() [2/2]

template<typename Derived>
template<typename NType>
FixedSegmentReturnType<... >::Type Eigen::SparseMatrixBase< Derived >::tail ( NType n)
inlineconstexpr
Returns
an expression of the last coefficients of *this with either dynamic or fixed sizes.

This is only for vectors (either row-vectors or column-vectors), i.e. matrices which are known at compile-time to have either one row or one column.

Parameters
nthe number of coefficients in the segment
Template Parameters
NTypethe type of the value handling the number of coefficients in the segment, typically Index.

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
RowVector4i v = RowVector4i::Random();
cout << "Here is the vector v:" << endl << v << endl;
cout << "Here is v.tail(2):" << endl << v.tail(2) << endl;
v.tail(2).setZero();
cout << "Now the vector v is:" << endl << v << endl;

Output:

Here is the vector v:
 1804289383  -465790871  1957747793 -1427598262
Here is v.tail(2):
 1957747793 -1427598262
Now the vector v is:
1804289383 -465790871          0          0

The number of coefficients n can also be specified at compile-time by passing Eigen::fix<N>, or Eigen::fix<N>(n) as arguments. See block() for the details.

Note
Even in the case that the returned expression has dynamic size, in the case when it is applied to a fixed-size vector, it inherits a fixed maximal size, which means that evaluating it does not cause a dynamic memory allocation.
See also
class Block, block(Index,Index)

◆ topLeftCorner() [1/3]

template<typename Derived>
template<int CRows, int CCols>
FixedBlockXpr< CRows, CCols >::Type Eigen::SparseMatrixBase< Derived >::topLeftCorner ( )
inlineconstexpr
Returns
an expression of a fixed-size top-left corner of *this.

The template parameters CRows and CCols are the number of rows and columns in the corner.

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
Matrix4i m = Matrix4i::Random();
cout << "Here is the matrix m:" << endl << m << endl;
cout << "Here is m.topLeftCorner<2,2>():" << endl;
cout << m.topLeftCorner<2, 2>() << endl;
m.topLeftCorner<2, 2>().setZero();
cout << "Now the matrix m is:" << endl << m << endl;

Output:

Here is the matrix m:
 1804289383 -1550966999  -782303108   336465782
 -465790871 -1122281286 -1843394476   278722862
 1957747793 -1364114958    35005211  2145174067
-1427598262  -102585885 -1852781081 -1045969719
Here is m.topLeftCorner<2,2>():
 1804289383 -1550966999
 -465790871 -1122281286
Now the matrix m is:
          0           0  -782303108   336465782
          0           0 -1843394476   278722862
 1957747793 -1364114958    35005211  2145174067
-1427598262  -102585885 -1852781081 -1045969719
Warning
This method returns a read-only expression for any sparse matrices.
See also
Sparse block operations
block(Index,Index,NRowsType,NColsType), class Block

◆ topLeftCorner() [2/3]

template<typename Derived>
template<int CRows, int CCols>
FixedBlockXpr< CRows, CCols >::Type Eigen::SparseMatrixBase< Derived >::topLeftCorner ( Index cRows,
Index cCols )
inlineconstexpr
Returns
an expression of a top-left corner of *this.
Template Parameters
CRowsnumber of rows in corner as specified at compile-time
CColsnumber of columns in corner as specified at compile-time
Parameters
cRowsnumber of rows in corner as specified at run-time
cColsnumber of columns in corner as specified at run-time

This function is mainly useful for corners where the number of rows is specified at compile-time and the number of columns is specified at run-time, or vice versa. The compile-time and run-time information should not contradict. In other words, cRows should equal CRows unless CRows is Dynamic, and the same for the number of columns.

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
Matrix4i m = Matrix4i::Random();
cout << "Here is the matrix m:" << endl << m << endl;
cout << "Here is m.topLeftCorner<2,Dynamic>(2,2):" << endl;
cout << m.topLeftCorner<2, Dynamic>(2, 2) << endl;
m.topLeftCorner<2, Dynamic>(2, 2).setZero();
cout << "Now the matrix m is:" << endl << m << endl;

Output:

Here is the matrix m:
 1804289383 -1550966999  -782303108   336465782
 -465790871 -1122281286 -1843394476   278722862
 1957747793 -1364114958    35005211  2145174067
-1427598262  -102585885 -1852781081 -1045969719
Here is m.topLeftCorner<2,Dynamic>(2,2):
 1804289383 -1550966999
 -465790871 -1122281286
Now the matrix m is:
          0           0  -782303108   336465782
          0           0 -1843394476   278722862
 1957747793 -1364114958    35005211  2145174067
-1427598262  -102585885 -1852781081 -1045969719
Warning
This method returns a read-only expression for any sparse matrices.
See also
Sparse block operations
class Block

◆ topLeftCorner() [3/3]

template<typename Derived>
template<typename NRowsType, typename NColsType>
FixedBlockXpr<...,... >::Type Eigen::SparseMatrixBase< Derived >::topLeftCorner ( NRowsType cRows,
NColsType cCols )
inlineconstexpr
Returns
an expression of a top-left corner of *this with either dynamic or fixed sizes.
Parameters
cRowsthe number of rows in the corner
cColsthe number of columns in the corner
Template Parameters
NRowsTypethe type of the value handling the number of rows in the block, typically Index.
NColsTypethe type of the value handling the number of columns in the block, typically Index.

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
Matrix4i m = Matrix4i::Random();
cout << "Here is the matrix m:" << endl << m << endl;
cout << "Here is m.topLeftCorner(2, 2):" << endl;
cout << m.topLeftCorner(2, 2) << endl;
m.topLeftCorner(2, 2).setZero();
cout << "Now the matrix m is:" << endl << m << endl;

Output:

Here is the matrix m:
 1804289383 -1550966999  -782303108   336465782
 -465790871 -1122281286 -1843394476   278722862
 1957747793 -1364114958    35005211  2145174067
-1427598262  -102585885 -1852781081 -1045969719
Here is m.topLeftCorner(2, 2):
 1804289383 -1550966999
 -465790871 -1122281286
Now the matrix m is:
          0           0  -782303108   336465782
          0           0 -1843394476   278722862
 1957747793 -1364114958    35005211  2145174067
-1427598262  -102585885 -1852781081 -1045969719

The number of rows blockRows and columns blockCols can also be specified at compile-time by passing Eigen::fix<N>, or Eigen::fix<N>(n) as arguments. See block() for the details.

Warning
This method returns a read-only expression for any sparse matrices.
See also
Sparse block operations
block(Index,Index,NRowsType,NColsType), class Block

◆ topRightCorner() [1/3]

template<typename Derived>
template<int CRows, int CCols>
FixedBlockXpr< CRows, CCols >::Type Eigen::SparseMatrixBase< Derived >::topRightCorner ( )
inlineconstexpr
Returns
an expression of a fixed-size top-right corner of *this.
Template Parameters
CRowsthe number of rows in the corner
CColsthe number of columns in the corner

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
Matrix4i m = Matrix4i::Random();
cout << "Here is the matrix m:" << endl << m << endl;
cout << "Here is m.topRightCorner<2,2>():" << endl;
cout << m.topRightCorner<2, 2>() << endl;
m.topRightCorner<2, 2>().setZero();
cout << "Now the matrix m is:" << endl << m << endl;

Output:

Here is the matrix m:
 1804289383 -1550966999  -782303108   336465782
 -465790871 -1122281286 -1843394476   278722862
 1957747793 -1364114958    35005211  2145174067
-1427598262  -102585885 -1852781081 -1045969719
Here is m.topRightCorner<2,2>():
 -782303108   336465782
-1843394476   278722862
Now the matrix m is:
 1804289383 -1550966999           0           0
 -465790871 -1122281286           0           0
 1957747793 -1364114958    35005211  2145174067
-1427598262  -102585885 -1852781081 -1045969719
Warning
This method returns a read-only expression for any sparse matrices.
See also
Sparse block operations
class Block, block<int,int>(Index,Index)

◆ topRightCorner() [2/3]

template<typename Derived>
template<int CRows, int CCols>
FixedBlockXpr< CRows, CCols >::Type Eigen::SparseMatrixBase< Derived >::topRightCorner ( Index cRows,
Index cCols )
inlineconstexpr
Returns
an expression of a top-right corner of *this.
Template Parameters
CRowsnumber of rows in corner as specified at compile-time
CColsnumber of columns in corner as specified at compile-time
Parameters
cRowsnumber of rows in corner as specified at run-time
cColsnumber of columns in corner as specified at run-time

This function is mainly useful for corners where the number of rows is specified at compile-time and the number of columns is specified at run-time, or vice versa. The compile-time and run-time information should not contradict. In other words, cRows should equal CRows unless CRows is Dynamic, and the same for the number of columns.

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
Matrix4i m = Matrix4i::Random();
cout << "Here is the matrix m:" << endl << m << endl;
cout << "Here is m.topRightCorner<2,Dynamic>(2,2):" << endl;
cout << m.topRightCorner<2, Dynamic>(2, 2) << endl;
m.topRightCorner<2, Dynamic>(2, 2).setZero();
cout << "Now the matrix m is:" << endl << m << endl;

Output:

Here is the matrix m:
 1804289383 -1550966999  -782303108   336465782
 -465790871 -1122281286 -1843394476   278722862
 1957747793 -1364114958    35005211  2145174067
-1427598262  -102585885 -1852781081 -1045969719
Here is m.topRightCorner<2,Dynamic>(2,2):
 -782303108   336465782
-1843394476   278722862
Now the matrix m is:
 1804289383 -1550966999           0           0
 -465790871 -1122281286           0           0
 1957747793 -1364114958    35005211  2145174067
-1427598262  -102585885 -1852781081 -1045969719
Warning
This method returns a read-only expression for any sparse matrices.
See also
Sparse block operations
class Block

◆ topRightCorner() [3/3]

template<typename Derived>
template<typename NRowsType, typename NColsType>
FixedBlockXpr<...,... >::Type Eigen::SparseMatrixBase< Derived >::topRightCorner ( NRowsType cRows,
NColsType cCols )
inlineconstexpr
Returns
an expression of a top-right corner of *this with either dynamic or fixed sizes.
Parameters
cRowsthe number of rows in the corner
cColsthe number of columns in the corner
Template Parameters
NRowsTypethe type of the value handling the number of rows in the block, typically Index.
NColsTypethe type of the value handling the number of columns in the block, typically Index.

Example with dynamic sizes:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
Matrix4i m = Matrix4i::Random();
cout << "Here is the matrix m:" << endl << m << endl;
cout << "Here is m.topRightCorner(2, 2):" << endl;
cout << m.topRightCorner(2, 2) << endl;
m.topRightCorner(2, 2).setZero();
cout << "Now the matrix m is:" << endl << m << endl;

Output:

Here is the matrix m:
 1804289383 -1550966999  -782303108   336465782
 -465790871 -1122281286 -1843394476   278722862
 1957747793 -1364114958    35005211  2145174067
-1427598262  -102585885 -1852781081 -1045969719
Here is m.topRightCorner(2, 2):
 -782303108   336465782
-1843394476   278722862
Now the matrix m is:
 1804289383 -1550966999           0           0
 -465790871 -1122281286           0           0
 1957747793 -1364114958    35005211  2145174067
-1427598262  -102585885 -1852781081 -1045969719

The number of rows blockRows and columns blockCols can also be specified at compile-time by passing Eigen::fix<N>, or Eigen::fix<N>(n) as arguments. See block() for the details.

Warning
This method returns a read-only expression for any sparse matrices.
See also
Sparse block operations
block(Index,Index,NRowsType,NColsType), class Block

◆ topRows() [1/2]

template<typename Derived>
template<int N>
NRowsBlockXpr< N >::Type Eigen::SparseMatrixBase< Derived >::topRows ( Index n = N)
inlineconstexpr
Returns
a block consisting of the top rows of *this.
Template Parameters
Nthe number of rows in the block as specified at compile-time
Parameters
nthe number of rows in the block as specified at run-time

The compile-time and run-time information should not contradict. In other words, n should equal N unless N is Dynamic.

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
Array44i a = Array44i::Random();
cout << "Here is the array a:" << endl << a << endl;
cout << "Here is a.topRows<2>():" << endl;
cout << a.topRows<2>() << endl;
a.topRows<2>().setZero();
cout << "Now the array a is:" << endl << a << endl;

Output:

Here is the array a:
 1804289383 -1550966999  -782303108   336465782
 -465790871 -1122281286 -1843394476   278722862
 1957747793 -1364114958    35005211  2145174067
-1427598262  -102585885 -1852781081 -1045969719
Here is a.topRows<2>():
 1804289383 -1550966999  -782303108   336465782
 -465790871 -1122281286 -1843394476   278722862
Now the array a is:
          0           0           0           0
          0           0           0           0
 1957747793 -1364114958    35005211  2145174067
-1427598262  -102585885 -1852781081 -1045969719
Warning
This method returns a read-write expression for row - major sparse matrices only. Otherwise, the returned expression is read-only.
See also
Sparse block operations
block(Index,Index,NRowsType,NColsType), class Block

◆ topRows() [2/2]

template<typename Derived>
template<typename NRowsType>
NRowsBlockXpr<... >::Type Eigen::SparseMatrixBase< Derived >::topRows ( NRowsType n)
inlineconstexpr
Returns
a block consisting of the top rows of *this.
Parameters
nthe number of rows in the block
Template Parameters
NRowsTypethe type of the value handling the number of rows in the block, typically Index.

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
Array44i a = Array44i::Random();
cout << "Here is the array a:" << endl << a << endl;
cout << "Here is a.topRows(2):" << endl;
cout << a.topRows(2) << endl;
a.topRows(2).setZero();
cout << "Now the array a is:" << endl << a << endl;

Output:

Here is the array a:
 1804289383 -1550966999  -782303108   336465782
 -465790871 -1122281286 -1843394476   278722862
 1957747793 -1364114958    35005211  2145174067
-1427598262  -102585885 -1852781081 -1045969719
Here is a.topRows(2):
 1804289383 -1550966999  -782303108   336465782
 -465790871 -1122281286 -1843394476   278722862
Now the array a is:
          0           0           0           0
          0           0           0           0
 1957747793 -1364114958    35005211  2145174067
-1427598262  -102585885 -1852781081 -1045969719

The number of rows n can also be specified at compile-time by passing Eigen::fix<N>, or Eigen::fix<N>(n) as arguments. See block() for the details.

Warning
This method returns a read-write expression for row - major sparse matrices only. Otherwise, the returned expression is read-only.
See also
Sparse block operations
block(Index,Index,NRowsType,NColsType), class Block

◆ twistedBy()

template<typename Derived>
SparseSymmetricPermutationProduct< Derived, Upper|Lower > Eigen::SparseMatrixBase< Derived >::twistedBy ( const PermutationMatrix< Dynamic, Dynamic, StorageIndex > & perm) const
inline
Returns
an expression of P H P^-1 where H is the matrix represented by *this

◆ unaryExpr()

template<typename Derived>
template<typename CustomUnaryOp>
const CwiseUnaryOp< CustomUnaryOp, const Derived > Eigen::SparseMatrixBase< Derived >::unaryExpr ( const CustomUnaryOp & func = CustomUnaryOp()) const
inlineconstexpr

Apply a unary operator coefficient-wise.

Parameters
[in]funcFunctor implementing the unary operator
Template Parameters
CustomUnaryOpType of func
Returns
An expression of a custom coefficient-wise unary operator func of *this

A lambda can be used to adapt a normal function to the functor interface expected by this method.

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
#include <Eigen/Core>
#include <iostream>
// define function to be applied coefficient-wise
double ramp(double x) {
if (x > 0)
return x;
else
return 0;
}
int main(int, char**) {
Eigen::Matrix4d m1 = Eigen::Matrix4d::Random();
std::cout << m1 << std::endl
<< "becomes: " << std::endl
<< m1.unaryExpr([](double x) { return ramp(x); }) << std::endl;
return 0;
}

Output:

-0.211  0.108  0.435 -0.198
 0.597  0.258  0.214 -0.782
-0.605 0.0268 -0.514 -0.563
 0.536  0.832  0.608  0.678
becomes: 
     0  0.108  0.435      0
 0.597  0.258  0.214      0
     0 0.0268      0      0
 0.536  0.832  0.608  0.678

Genuine functors allow for more possibilities, for instance it may contain a state.

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
#include <Eigen/Core>
#include <iostream>
// define a custom template unary functor
template <typename Scalar>
struct CwiseClampOp {
CwiseClampOp(const Scalar& inf, const Scalar& sup) : m_inf(inf), m_sup(sup) {}
const Scalar operator()(const Scalar& x) const { return x < m_inf ? m_inf : (x > m_sup ? m_sup : x); }
Scalar m_inf, m_sup;
};
int main(int, char**) {
Eigen::Matrix4d m1 = Eigen::Matrix4d::Random();
std::cout << m1 << std::endl
<< "becomes: " << std::endl
<< m1.unaryExpr(CwiseClampOp<double>(-0.5, 0.5)) << std::endl;
return 0;
}

Output:

-0.211  0.108  0.435 -0.198
 0.597  0.258  0.214 -0.782
-0.605 0.0268 -0.514 -0.563
 0.536  0.832  0.608  0.678
becomes: 
-0.211  0.108  0.435 -0.198
   0.5  0.258  0.214   -0.5
  -0.5 0.0268   -0.5   -0.5
   0.5    0.5    0.5    0.5

This method does not change the sparsity of *this: the unary function is applied to explicitly stored coefficients only.

See also
SparseCompressedBase::coeffs()
unaryViewExpr, binaryExpr, class CwiseUnaryOp

◆ unaryViewExpr() [1/2]

template<typename Derived>
template<typename CustomViewOp>
CwiseUnaryView< CustomViewOp, Derived > Eigen::SparseMatrixBase< Derived >::unaryViewExpr ( const CustomViewOp & func = CustomViewOp())
inlineconstexpr
Returns
a non-const expression of a custom coefficient-wise unary view func of *this

The template parameter CustomUnaryOp is the type of the functor of the custom unary operator.

This method does not change the sparsity of *this: the unary function is applied to explicitly stored coefficients only.

See also
SparseCompressedBase::coeffs()
unaryExpr, binaryExpr, class CwiseUnaryOp

◆ unaryViewExpr() [2/2]

template<typename Derived>
template<typename CustomViewOp>
const CwiseUnaryView< CustomViewOp, const Derived > Eigen::SparseMatrixBase< Derived >::unaryViewExpr ( const CustomViewOp & func = CustomViewOp()) const
inlineconstexpr
Returns
a const expression of a custom coefficient-wise unary operator func of *this

The template parameter CustomUnaryOp is the type of the functor of the custom unary operator.

Example:

// SPDX-FileCopyrightText: The Eigen Authors
// SPDX-License-Identifier: MPL-2.0
#include <Eigen/Core>
#include <iostream>
// define a custom template unary functor
template <typename Scalar>
struct CwiseClampOp {
CwiseClampOp(const Scalar& inf, const Scalar& sup) : m_inf(inf), m_sup(sup) {}
const Scalar operator()(const Scalar& x) const { return x < m_inf ? m_inf : (x > m_sup ? m_sup : x); }
Scalar m_inf, m_sup;
};
int main(int, char**) {
Eigen::Matrix4d m1 = Eigen::Matrix4d::Random();
std::cout << m1 << std::endl
<< "becomes: " << std::endl
<< m1.unaryExpr(CwiseClampOp<double>(-0.5, 0.5)) << std::endl;
return 0;
}

Output:

-0.211  0.108  0.435 -0.198
 0.597  0.258  0.214 -0.782
-0.605 0.0268 -0.514 -0.563
 0.536  0.832  0.608  0.678
becomes: 
-0.211  0.108  0.435 -0.198
   0.5  0.258  0.214   -0.5
  -0.5 0.0268   -0.5   -0.5
   0.5    0.5    0.5    0.5

This method does not change the sparsity of *this: the unary function is applied to explicitly stored coefficients only.

See also
SparseCompressedBase::coeffs()
unaryExpr, binaryExpr, class CwiseUnaryOp

The documentation for this class was generated from the following files: