SparseVector< _Scalar, _Options, _Index > Class Template Reference

a sparse vector class More...

#include <SparseVector.h>

Inheritance diagram for SparseVector< _Scalar, _Options, _Index >:

Public Member Functions
const CwiseBinaryOp< CustomBinaryOp, const SparseVector< _Scalar, _Options, _Index >, const OtherDerived >	binaryExpr (const Eigen::SparseMatrixBase< OtherDerived > &other, const CustomBinaryOp &func=CustomBinaryOp()) const
internal::cast_return_type< SparseVector< _Scalar, _Options, _Index >, constCwiseUnaryOp< internal::scalar_cast_op< typenameinternal::traits< SparseVector< _Scalar, _Options, _Index > >::Scalar, NewType >, constDerived > >::type	cast () const
Scalar &	coeffRef (Index i)
SparseInnerVectorSet< SparseVector< _Scalar, _Options, _Index >, 1 >	col (Index j)
const SparseInnerVectorSet< SparseVector< _Scalar, _Options, _Index >, 1 >	col (Index j) const
ConjugateReturnType	conjugate () const
const CwiseUnaryOp< internal::scalar_abs_op< Scalar >, const SparseVector< _Scalar, _Options, _Index > >	cwiseAbs () const
const CwiseUnaryOp< internal::scalar_abs2_op< Scalar >, const SparseVector< _Scalar, _Options, _Index > >	cwiseAbs2 () const
const CwiseUnaryOp< std::binder1st< std::equal_to< Scalar > >, const SparseVector< _Scalar, _Options, _Index > >	cwiseEqual (const Scalar &s) const
const CwiseUnaryOp< internal::scalar_inverse_op< Scalar >, const SparseVector< _Scalar, _Options, _Index > >	cwiseInverse () const
const CwiseUnaryOp< internal::scalar_sqrt_op< Scalar >, const SparseVector< _Scalar, _Options, _Index > >	cwiseSqrt () const
SparseVector< _Scalar, _Options, _Index > &	derived ()
const SparseVector< _Scalar, _Options, _Index > &	derived () const
const	EIGEN_CWISE_PRODUCT_RETURN_TYPE (SparseVector< _Scalar, _Options, _Index >, OtherDerived) cwiseProduct(const Eigen
EIGEN_DEPRECATED void	endFill ()
const internal::eval< SparseVector< _Scalar, _Options, _Index > >::type	eval () const
EIGEN_DEPRECATED Scalar &	fill (Index i)
EIGEN_DEPRECATED Scalar &	fill (Index r, Index c)
EIGEN_DEPRECATED Scalar &	fillrand (Index i)
EIGEN_DEPRECATED Scalar &	fillrand (Index r, Index c)
NonConstImagReturnType	imag ()
const ImagReturnType	imag () const
SparseInnerVectorSet< SparseVector< _Scalar, _Options, _Index >, 1 >	innerVector (Index outer)
const SparseInnerVectorSet< SparseVector< _Scalar, _Options, _Index >, 1 >	innerVector (Index outer) const
SparseInnerVectorSet< SparseVector< _Scalar, _Options, _Index >, Dynamic >	innerVectors (Index outerStart, Index outerSize)
const SparseInnerVectorSet< SparseVector< _Scalar, _Options, _Index >, Dynamic >	innerVectors (Index outerStart, Index outerSize) const
SparseInnerVectorSet< SparseVector< _Scalar, _Options, _Index >, Dynamic >	middleCols (Index start, Index size)
const SparseInnerVectorSet< SparseVector< _Scalar, _Options, _Index >, Dynamic >	middleCols (Index start, Index size) const
SparseInnerVectorSet< SparseVector< _Scalar, _Options, _Index >, Dynamic >	middleRows (Index start, Index size)
const SparseInnerVectorSet< SparseVector< _Scalar, _Options, _Index >, Dynamic >	middleRows (Index start, Index size) const
Index	nonZeros () const
const SparseDenseProductReturnType< SparseVector< _Scalar, _Options, _Index >, OtherDerived >::Type	operator* (const MatrixBase< OtherDerived > &other) const
const ScalarMultipleReturnType	operator* (const Scalar &scalar) const
const SparseSparseProductReturnType< SparseVector< _Scalar, _Options, _Index >, OtherDerived >::Type	operator* (const SparseMatrixBase< OtherDerived > &other) const
const CwiseUnaryOp< internal::scalar_multiple2_op< Scalar, std::complex< Scalar > >, const SparseVector< _Scalar, _Options, _Index > >	operator* (const std::complex< Scalar > &scalar) const
const CwiseUnaryOp< internal::scalar_opposite_op< typename internal::traits< SparseVector< _Scalar, _Options, _Index > >::Scalar >, const SparseVector< _Scalar, _Options, _Index > >	operator- () const
const CwiseUnaryOp< internal::scalar_quotient1_op< typename internal::traits< SparseVector< _Scalar, _Options, _Index > >::Scalar >, const SparseVector< _Scalar, _Options, _Index > >	operator/ (const Scalar &scalar) const
NonConstRealReturnType	real ()
RealReturnType	real () const
SparseInnerVectorSet< SparseVector< _Scalar, _Options, _Index >, 1 >	row (Index i)
const SparseInnerVectorSet< SparseVector< _Scalar, _Options, _Index >, 1 >	row (Index i) const
Index	size () const
EIGEN_DEPRECATED void	startFill (Index reserve)
Scalar	sum () const
SparseSymmetricPermutationProduct< SparseVector< _Scalar, _Options, _Index >, Upper|Lower >	twistedBy (const PermutationMatrix< Dynamic, Dynamic, Index > &perm) const
const CwiseUnaryOp< CustomUnaryOp, const SparseVector< _Scalar, _Options, _Index > >	unaryExpr (const CustomUnaryOp &func=CustomUnaryOp()) const
	Apply a unary operator coefficient-wise.
const CwiseUnaryView< CustomViewOp, const SparseVector< _Scalar, _Options, _Index > >	unaryViewExpr (const CustomViewOp &func=CustomViewOp()) const
	~SparseVector ()

Detailed Description

template<typename _Scalar, int _Options, typename _Index>
class Eigen::SparseVector< _Scalar, _Options, _Index >

a sparse vector class

Template Parameters

_Scalar

the scalar type, i.e. the type of the coefficients

See http://www.netlib.org/linalg/html_templates/node91.html for details on the storage scheme.

This class can be extended with the help of the plugin mechanism described on the page Customizing/Extending Eigen by defining the preprocessor symbol EIGEN_SPARSEVECTOR_PLUGIN.

Constructor & Destructor Documentation

~SparseVector()

template<typename _Scalar, int _Options, typename _Index>

~SparseVector ( )

inline

Destructor

Member Function Documentation

binaryExpr()

const CwiseBinaryOp< CustomBinaryOp, const SparseVector< _Scalar, _Options, _Index >, const OtherDerived > binaryExpr ( const Eigen::SparseMatrixBase< OtherDerived > & other, const CustomBinaryOp & func = CustomBinaryOp() ) const

inlineinherited

Returns

an expression of the difference of *this and other

Note

If you want to substract a given scalar from all coefficients, see Cwise::operator-().

See also

class CwiseBinaryOp, operator-=()

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+=()

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:

#include <Eigen/Core>
#include <iostream>
using namespace Eigen;
using namespace std;
 
// define a custom template binary functor
template<typename Scalar> struct MakeComplexOp {
  EIGEN_EMPTY_STRUCT_CTOR(MakeComplexOp)
  typedef complex<Scalar> result_type;
  complex<Scalar> operator()(const Scalar& a, const Scalar& b) const { return complex<Scalar>(a,b); }
};
 
int main(int, char**)
{
  Matrix4d m1 = Matrix4d::Random(), m2 = Matrix4d::Random();
  cout << m1.binaryExpr(m2, MakeComplexOp<double>()) << endl;
  return 0;
}

Output:

   (0.68,0.271)  (0.823,-0.967) (-0.444,-0.687)   (-0.27,0.998)
 (-0.211,0.435) (-0.605,-0.514)  (0.108,-0.198) (0.0268,-0.563)
 (0.566,-0.717)  (-0.33,-0.726) (-0.0452,-0.74)  (0.904,0.0259)
  (0.597,0.214)   (0.536,0.608)  (0.258,-0.782)   (0.832,0.678)

See also

class CwiseBinaryOp, operator+(), operator-(), cwiseProduct()

cast()

internal::cast_return_type< SparseVector< _Scalar, _Options, _Index >, constCwiseUnaryOp< internal::scalar_cast_op< typenameinternal::traits< SparseVector< _Scalar, _Options, _Index > >::Scalar, NewType >, constDerived > >::type cast ( ) const

inlineinherited

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.

See also

class CwiseUnaryOp

coeffRef()

template<typename _Scalar, int _Options, typename _Index>

Scalar & coeffRef ( Index i )

inline

Returns

a reference to the coefficient value at given index i This operation involes a log(rho*size) binary search. If the coefficient does not exist yet, then a sorted insertion into a sequential buffer is performed.

This insertion might be very costly if the number of nonzeros above i is large.

col() [1/2]

SparseInnerVectorSet< SparseVector< _Scalar, _Options, _Index >, 1 > col ( Index i )

inherited

Returns

the i-th column of the matrix *this. For column-major matrix only.

col() [2/2]

const SparseInnerVectorSet< SparseVector< _Scalar, _Options, _Index >, 1 > col ( Index i ) const

inherited

Returns

the i-th column of the matrix *this. For column-major matrix only. (read-only version)

conjugate()

ConjugateReturnType conjugate ( ) const

inlineinherited

Returns

an expression of the complex conjugate of *this.

See also

adjoint()

cwiseAbs()

const CwiseUnaryOp< internal::scalar_abs_op< Scalar >, const SparseVector< _Scalar, _Options, _Index > > cwiseAbs ( ) const

inlineinherited

Returns

an expression of the coefficient-wise absolute value of *this

Example:

MatrixXd m(2,3);
m << 2, -4, 6,   
     -5, 1, 0;
cout << m.cwiseAbs() << endl;

Output:

2 4 6
5 1 0

See also

cwiseAbs2()

cwiseAbs2()

const CwiseUnaryOp< internal::scalar_abs2_op< Scalar >, const SparseVector< _Scalar, _Options, _Index > > cwiseAbs2 ( ) const

inlineinherited

Returns

an expression of the coefficient-wise squared absolute value of *this

Example:

MatrixXd m(2,3);
m << 2, -4, 6,   
     -5, 1, 0;
cout << m.cwiseAbs2() << endl;

Output:

 4 16 36
25  1  0

See also

cwiseAbs()

cwiseEqual()

const CwiseUnaryOp< std::binder1st< std::equal_to< Scalar > >, const SparseVector< _Scalar, _Options, _Index > > cwiseEqual ( const Scalar & s ) const

inlineinherited

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

cwiseInverse()

const CwiseUnaryOp< internal::scalar_inverse_op< Scalar >, const SparseVector< _Scalar, _Options, _Index > > cwiseInverse ( ) const

inlineinherited

Returns

an expression of the coefficient-wise inverse of *this.

Example:

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

See also

cwiseProduct()

cwiseSqrt()

const CwiseUnaryOp< internal::scalar_sqrt_op< Scalar >, const SparseVector< _Scalar, _Options, _Index > > cwiseSqrt ( ) const

inlineinherited

Returns

an expression of the coefficient-wise square root of *this.

Example:

Vector3d v(1,2,4);
cout << v.cwiseSqrt() << endl;

Output:

1
1.41
2

See also

cwisePow(), cwiseSquare()

derived() [1/2]

SparseVector< _Scalar, _Options, _Index > & derived ( )

inlineinherited

Returns

a reference to the derived object

derived() [2/2]

const SparseVector< _Scalar, _Options, _Index > & derived ( ) const

inlineinherited

Returns

a const reference to the derived object

EIGEN_CWISE_PRODUCT_RETURN_TYPE()

const EIGEN_CWISE_PRODUCT_RETURN_TYPE ( SparseVector< _Scalar, _Options, _Index > , OtherDerived  ) const

inlineinherited

Returns

an expression of the Schur product (coefficient wise product) of *this and other

Example:

Matrix3i a = Matrix3i::Random(), b = Matrix3i::Random();
Matrix3i c = a.cwiseProduct(b);
cout << "a:\n" << a << "\nb:\n" << b << "\nc:\n" << c << endl;
 

Output:

a:
 7  6 -3
-2  9  6
 6 -6 -5
b:
 1 -3  9
 0  0  3
 3  9  5
c:
  7 -18 -27
  0   0  18
 18 -54 -25

See also

class CwiseBinaryOp, cwiseAbs2

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:

MatrixXi m(2,2);
m << 1, 0,
     1, 1;
cout << "Comparing m with identity matrix:" << endl;
cout << m.cwiseEqual(MatrixXi::Identity(2,2)) << endl;
int count = m.cwiseEqual(MatrixXi::Identity(2,2)).count();
cout << "Number of coefficients that are equal: " << count << endl;

Output:

Comparing m with identity matrix:
1 1
0 1
Number of coefficients that are equal: 3

See also

cwiseNotEqual(), isApprox(), isMuchSmallerThan()

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:

MatrixXi m(2,2);
m << 1, 0,
     1, 1;
cout << "Comparing m with identity matrix:" << endl;
cout << m.cwiseNotEqual(MatrixXi::Identity(2,2)) << endl;
int 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()

Returns

an expression of the coefficient-wise min of *this and other

Example:

Vector3d v(2,3,4), w(4,2,3);
cout << v.cwiseMin(w) << endl;

Output:

2
2
3

See also

class CwiseBinaryOp, max()

Returns

an expression of the coefficient-wise min of *this and scalar other

See also

class CwiseBinaryOp, min()

Returns

an expression of the coefficient-wise max of *this and other

Example:

Vector3d v(2,3,4), w(4,2,3);
cout << v.cwiseMax(w) << endl;

Output:

4
3
4

See also

class CwiseBinaryOp, min()

Returns

an expression of the coefficient-wise max of *this and scalar other

See also

class CwiseBinaryOp, min()

Returns

an expression of the coefficient-wise quotient of *this and other

Example:

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()

Returns

the number of rows.

See also

cols()

Returns

the number of columns.

See also

rows()

Returns

the number of coefficients, which is rows()*cols().

See also

rows(), cols().

Returns

the number of nonzero coefficients which is in practice the number of stored coefficients.

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.

Returns

the size of the storage major dimension, i.e., the number of columns for a columns major matrix, and the number of rows otherwise

the size of the inner dimension according to the storage order, i.e., the number of rows for a columns major matrix, and the number of cols otherwise

endFill()

template<typename _Scalar, int _Options, typename _Index>

EIGEN_DEPRECATED void endFill ( )

inline

eval()

const internal::eval< SparseVector< _Scalar, _Options, _Index > >::type eval ( ) const

inlineinherited

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.

fill() [1/2]

template<typename _Scalar, int _Options, typename _Index>

EIGEN_DEPRECATED Scalar & fill ( Index i )

inline

fill() [2/2]

template<typename _Scalar, int _Options, typename _Index>

EIGEN_DEPRECATED Scalar & fill ( Index r, Index c )

inline

fillrand() [1/2]

template<typename _Scalar, int _Options, typename _Index>

EIGEN_DEPRECATED Scalar & fillrand ( Index i )

inline

fillrand() [2/2]

template<typename _Scalar, int _Options, typename _Index>

EIGEN_DEPRECATED Scalar & fillrand ( Index r, Index c )

inline

imag() [1/2]

NonConstImagReturnType imag ( )

inlineinherited

Returns

a non const expression of the imaginary part of *this.

See also

real()

imag() [2/2]

const ImagReturnType imag ( ) const

inlineinherited

Returns

an read-only expression of the imaginary part of *this.

See also

real()

innerVector() [1/2]

SparseInnerVectorSet< SparseVector< _Scalar, _Options, _Index >, 1 > innerVector ( Index outer )

inherited

Returns

the outer -th column (resp. row) of the matrix *this if *this is col-major (resp. row-major).

innerVector() [2/2]

const SparseInnerVectorSet< SparseVector< _Scalar, _Options, _Index >, 1 > innerVector ( Index outer ) const

inherited

Returns

the outer -th column (resp. row) of the matrix *this if *this is col-major (resp. row-major). Read-only.

innerVectors() [1/2]

SparseInnerVectorSet< SparseVector< _Scalar, _Options, _Index >, Dynamic > innerVectors ( Index outerStart, Index outerSize )

inherited

Returns

the outer -th column (resp. row) of the matrix *this if *this is col-major (resp. row-major).

innerVectors() [2/2]

const SparseInnerVectorSet< SparseVector< _Scalar, _Options, _Index >, Dynamic > innerVectors ( Index outerStart, Index outerSize ) const

inherited

Returns

the outer -th column (resp. row) of the matrix *this if *this is col-major (resp. row-major). Read-only.

middleCols() [1/2]

SparseInnerVectorSet< SparseVector< _Scalar, _Options, _Index >, Dynamic > middleCols ( Index start, Index size )

inherited

Returns

the i-th column of the matrix *this. For column-major matrix only.

middleCols() [2/2]

const SparseInnerVectorSet< SparseVector< _Scalar, _Options, _Index >, Dynamic > middleCols ( Index start, Index size ) const

inherited

Returns

the i-th column of the matrix *this. For column-major matrix only. (read-only version)

middleRows() [1/2]

SparseInnerVectorSet< SparseVector< _Scalar, _Options, _Index >, Dynamic > middleRows ( Index start, Index size )

inherited

Returns

the i-th row of the matrix *this. For row-major matrix only.

middleRows() [2/2]

const SparseInnerVectorSet< SparseVector< _Scalar, _Options, _Index >, Dynamic > middleRows ( Index start, Index size ) const

inherited

Returns

the i-th row of the matrix *this. For row-major matrix only. (read-only version)

nonZeros()

template<typename _Scalar, int _Options, typename _Index>

Index nonZeros ( ) const

inline

Returns

the number of non zero coefficients

operator*() [1/4]

const SparseDenseProductReturnType< SparseVector< _Scalar, _Options, _Index >, OtherDerived >::Type operator* ( const MatrixBase< OtherDerived > & other ) const

inlineinherited

sparse * dense (returns a dense object unless it is an outer product)

operator*() [2/4]

const ScalarMultipleReturnType operator* ( const Scalar & scalar ) const

inlineinherited

Returns

an expression of *this scaled by the scalar factor scalar

operator*() [3/4]

const SparseSparseProductReturnType< SparseVector< _Scalar, _Options, _Index >, OtherDerived >::Type operator* ( const SparseMatrixBase< OtherDerived > & other ) const

inlineinherited

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

where ref is a meaningful non zero reference value.

operator*() [4/4]

const CwiseUnaryOp< internal::scalar_multiple2_op< Scalar, std::complex< Scalar > >, const SparseVector< _Scalar, _Options, _Index > > operator* ( const std::complex< Scalar > & scalar ) const

inlineinherited

Overloaded for efficient real matrix times complex scalar value

operator-()

const CwiseUnaryOp< internal::scalar_opposite_op< typename internal::traits< SparseVector< _Scalar, _Options, _Index > >::Scalar >, const SparseVector< _Scalar, _Options, _Index > > operator- ( ) const

inlineinherited

Returns

an expression of the opposite of *this

operator/()

const CwiseUnaryOp< internal::scalar_quotient1_op< typename internal::traits< SparseVector< _Scalar, _Options, _Index > >::Scalar >, const SparseVector< _Scalar, _Options, _Index > > operator/ ( const Scalar & scalar ) const

inlineinherited

Returns

an expression of *this divided by the scalar value scalar

real() [1/2]

NonConstRealReturnType real ( )

inlineinherited

Returns

a non const expression of the real part of *this.

See also

imag()

real() [2/2]

RealReturnType real ( ) const

inlineinherited

Returns

a read-only expression of the real part of *this.

See also

imag()

row() [1/2]

SparseInnerVectorSet< SparseVector< _Scalar, _Options, _Index >, 1 > row ( Index i )

inherited

Returns

the i-th row of the matrix *this. For row-major matrix only.

row() [2/2]

const SparseInnerVectorSet< SparseVector< _Scalar, _Options, _Index >, 1 > row ( Index i ) const

inherited

Returns

the i-th row of the matrix *this. For row-major matrix only. (read-only version)

size()

Index size ( ) const

inlineinherited

Returns

the number of coefficients, which is rows()*cols().

See also

rows(), cols(), SizeAtCompileTime.

startFill()

template<typename _Scalar, int _Options, typename _Index>

EIGEN_DEPRECATED void startFill ( Index reserve )

inline

sum()

template<typename _Scalar, int _Options, typename _Index>

internal::traits< SparseVector< _Scalar, _Options, _Index > >::Scalar sum

(

)

const

Overloaded for performance

twistedBy()

SparseSymmetricPermutationProduct< SparseVector< _Scalar, _Options, _Index >, Upper|Lower > twistedBy ( const PermutationMatrix< Dynamic, Dynamic, Index > & perm ) const

inlineinherited

Returns

an expression of P H P^-1 where H is the matrix represented by *this

unaryExpr()

const CwiseUnaryOp< CustomUnaryOp, const SparseVector< _Scalar, _Options, _Index > > unaryExpr ( const CustomUnaryOp & func = CustomUnaryOp() ) const

inlineinherited

Apply a unary operator coefficient-wise.

Parameters

[in]

func

Functor implementing the unary operator

Template Parameters

CustomUnaryOp

Type of func

Returns

An expression of a custom coefficient-wise unary operator func of *this

The function ptr_fun() from the C++ standard library can be used to make functors out of normal functions.

Example:

#include <Eigen/Core>
#include <iostream>
using namespace Eigen;
using namespace std;
 
// define function to be applied coefficient-wise
double ramp(double x)
{
  if (x > 0)
    return x;
  else 
    return 0;
}
 
int main(int, char**)
{
  Matrix4d m1 = Matrix4d::Random();
  cout << m1 << endl << "becomes: " << endl << m1.unaryExpr(ptr_fun(ramp)) << endl;
  return 0;
}

Output:

   0.68   0.823  -0.444   -0.27
 -0.211  -0.605   0.108  0.0268
  0.566   -0.33 -0.0452   0.904
  0.597   0.536   0.258   0.832
becomes: 
  0.68  0.823      0      0
     0      0  0.108 0.0268
 0.566      0      0  0.904
 0.597  0.536  0.258  0.832

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

Example:

#include <Eigen/Core>
#include <iostream>
using namespace Eigen;
using namespace std;
 
// 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**)
{
  Matrix4d m1 = Matrix4d::Random();
  cout << m1 << endl << "becomes: " << endl << m1.unaryExpr(CwiseClampOp<double>(-0.5,0.5)) << endl;
  return 0;
}

Output:

   0.68   0.823  -0.444   -0.27
 -0.211  -0.605   0.108  0.0268
  0.566   -0.33 -0.0452   0.904
  0.597   0.536   0.258   0.832
becomes: 
    0.5     0.5  -0.444   -0.27
 -0.211    -0.5   0.108  0.0268
    0.5   -0.33 -0.0452     0.5
    0.5     0.5   0.258     0.5

See also

class CwiseUnaryOp, class CwiseBinaryOp

unaryViewExpr()

const CwiseUnaryView< CustomViewOp, const SparseVector< _Scalar, _Options, _Index > > unaryViewExpr ( const CustomViewOp & func = CustomViewOp() ) const

inlineinherited

Returns

an 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:

#include <Eigen/Core>
#include <iostream>
using namespace Eigen;
using namespace std;
 
// 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**)
{
  Matrix4d m1 = Matrix4d::Random();
  cout << m1 << endl << "becomes: " << endl << m1.unaryExpr(CwiseClampOp<double>(-0.5,0.5)) << endl;
  return 0;
}

Output:

   0.68   0.823  -0.444   -0.27
 -0.211  -0.605   0.108  0.0268
  0.566   -0.33 -0.0452   0.904
  0.597   0.536   0.258   0.832
becomes: 
    0.5     0.5  -0.444   -0.27
 -0.211    -0.5   0.108  0.0268
    0.5   -0.33 -0.0452     0.5
    0.5     0.5   0.258     0.5

See also

class CwiseUnaryOp, class CwiseBinaryOp

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

• SparseUtil.h
• SparseVector.h
• SparseRedux.h