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SparseMatrixBase< Derived > Class Template Reference
SparseCore module

Detailed Description

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

Base class of any sparse matrices or sparse expressions.

Template Parameters
DerivedThis class can be extended with the help of the plugin mechanism described on the page Customizing/Extending Eigen by defining the preprocessor symbol EIGEN_SPARSEMATRIXBASE_PLUGIN.
+ Inheritance diagram for SparseMatrixBase< Derived >:

Public Types

enum  {
  RowsAtCompileTime,
  ColsAtCompileTime,
  SizeAtCompileTime ,
  IsVectorAtCompileTime,
  Flags,
  CoeffReadCost
}
 

Public Member Functions

template<typename CustomBinaryOp , typename OtherDerived >
const CwiseBinaryOp
< CustomBinaryOp, const
Derived, const OtherDerived > 		binaryExpr (const Eigen::SparseMatrixBase< OtherDerived > &other, const CustomBinaryOp &func=CustomBinaryOp()) const
 
Block< Derived > block (Index startRow, Index startCol, Index blockRows, Index blockCols)
 
const Block< const Derived > block (Index startRow, Index startCol, Index blockRows, Index blockCols) const
 
template<int BlockRows, int BlockCols>
Block< Derived, BlockRows,
BlockCols > 		block (Index startRow, Index startCol)
 
template<int BlockRows, int BlockCols>
const Block< const Derived,
BlockRows, BlockCols > 		block (Index startRow, Index startCol) const
 
template<int BlockRows, int BlockCols>
Block< Derived, BlockRows,
BlockCols > 		block (Index startRow, Index startCol, Index blockRows, Index blockCols)
 
template<int BlockRows, int BlockCols>
const Block< const Derived,
BlockRows, BlockCols > 		block (Index startRow, Index startCol, Index blockRows, Index blockCols) const
 
Block< Derived > bottomLeftCorner (Index cRows, Index cCols)
 
const Block< const Derived > bottomLeftCorner (Index cRows, Index cCols) const
 
template<int CRows, int CCols>
Block< Derived, CRows, CCols > bottomLeftCorner ()
 
template<int CRows, int CCols>
const Block< const Derived,
CRows, CCols > 		bottomLeftCorner () const
 
template<int CRows, int CCols>
Block< Derived, CRows, CCols > bottomLeftCorner (Index cRows, Index cCols)
 
template<int CRows, int CCols>
const Block< const Derived,
CRows, CCols > 		bottomLeftCorner (Index cRows, Index cCols) const
 
Block< Derived > bottomRightCorner (Index cRows, Index cCols)
 
const Block< const Derived > bottomRightCorner (Index cRows, Index cCols) const
 
template<int CRows, int CCols>
Block< Derived, CRows, CCols > bottomRightCorner ()
 
template<int CRows, int CCols>
const Block< const Derived,
CRows, CCols > 		bottomRightCorner () const
 
template<int CRows, int CCols>
Block< Derived, CRows, CCols > bottomRightCorner (Index cRows, Index cCols)
 
template<int CRows, int CCols>
const Block< const Derived,
CRows, CCols > 		bottomRightCorner (Index cRows, Index cCols) const
 
RowsBlockXpr bottomRows (Index n)
 
ConstRowsBlockXpr bottomRows (Index n) const
 
template<int N>
NRowsBlockXpr< N >::Type bottomRows (Index n=N)
 
template<int N>
ConstNRowsBlockXpr< N >::Type bottomRows (Index n=N) const
 
template<typename NewType >
internal::cast_return_type
< Derived, const CwiseUnaryOp
< internal::scalar_cast_op
< typename internal::traits
< Derived >::Scalar, NewType >
, const Derived > >::type 		cast () const
 
ColXpr col (Index i)
 
ConstColXpr col (Index i) const
 
Index cols () const
 
ConjugateReturnType conjugate () const
 
const CwiseUnaryOp
< internal::scalar_abs_op
< Scalar >, const Derived > 		cwiseAbs () const
 
const CwiseUnaryOp
< internal::scalar_abs2_op
< Scalar >, const Derived > 		cwiseAbs2 () const
 
template<typename OtherDerived >
const CwiseBinaryOp
< std::equal_to< Scalar >
, const Derived, const
OtherDerived > 		cwiseEqual (const Eigen::SparseMatrixBase< OtherDerived > &other) const
 
const CwiseScalarEqualReturnType cwiseEqual (const Scalar &s) const
 
const CwiseUnaryOp
< internal::scalar_inverse_op
< Scalar >, const Derived > 		cwiseInverse () const
 
template<typename OtherDerived >
const CwiseBinaryOp
< internal::scalar_max_op
< Scalar >, const Derived,
const OtherDerived > 		cwiseMax (const Eigen::SparseMatrixBase< OtherDerived > &other) const
 
const CwiseBinaryOp
< internal::scalar_max_op
< Scalar >, const Derived,
const ConstantReturnType > 		cwiseMax (const Scalar &other) const
 
template<typename OtherDerived >
const CwiseBinaryOp
< internal::scalar_min_op
< Scalar >, const Derived,
const OtherDerived > 		cwiseMin (const Eigen::SparseMatrixBase< OtherDerived > &other) const
 
const CwiseBinaryOp
< internal::scalar_min_op
< Scalar >, const Derived,
const ConstantReturnType > 		cwiseMin (const Scalar &other) const
 
template<typename OtherDerived >
const CwiseBinaryOp
< std::not_equal_to< Scalar >
, const Derived, const
OtherDerived > 		cwiseNotEqual (const Eigen::SparseMatrixBase< OtherDerived > &other) const
 
template<typename OtherDerived >
const CwiseBinaryOp
< internal::scalar_product_op
< typename Derived::Scalar,
typename OtherDerived::Scalar >
, const Derived, const
OtherDerived > 		cwiseProduct (const Eigen::SparseMatrixBase< OtherDerived > &other) const
 
template<typename OtherDerived >
const CwiseBinaryOp
< internal::scalar_quotient_op
< Scalar >, const Derived,
const OtherDerived > 		cwiseQuotient (const Eigen::SparseMatrixBase< OtherDerived > &other) const
 
const CwiseUnaryOp
< internal::scalar_sqrt_op
< Scalar >, const Derived > 		cwiseSqrt () const
 
Derived & derived ()
 
const Derived & derived () const
 
const internal::eval< Derived >
::type 		eval () const
 
SegmentReturnType head (Index n)
 
ConstSegmentReturnType head (Index n) const
 
template<int N>
FixedSegmentReturnType< N >::Type head (Index n=N)
 
template<int N>
ConstFixedSegmentReturnType< N >
::Type 		head (Index n=N) const
 
const ImagReturnType imag () const
 
NonConstImagReturnType imag ()
 
Index innerSize () const
 
InnerVectorReturnType innerVector (Index outer)
 
const ConstInnerVectorReturnType innerVector (Index outer) const
 
InnerVectorsReturnType innerVectors (Index outerStart, Index outerSize)
 
const ConstInnerVectorsReturnType innerVectors (Index outerStart, Index outerSize) const
 
bool isVector () const
 
ColsBlockXpr leftCols (Index n)
 
ConstColsBlockXpr leftCols (Index n) const
 
template<int N>
NColsBlockXpr< N >::Type leftCols (Index n=N)
 
template<int N>
ConstNColsBlockXpr< N >::Type leftCols (Index n=N) const
 
ColsBlockXpr middleCols (Index startCol, Index numCols)
 
ConstColsBlockXpr middleCols (Index startCol, Index numCols) const
 
template<int N>
NColsBlockXpr< N >::Type middleCols (Index startCol, Index n=N)
 
template<int N>
ConstNColsBlockXpr< N >::Type middleCols (Index startCol, Index n=N) const
 
RowsBlockXpr middleRows (Index startRow, Index n)
 
ConstRowsBlockXpr middleRows (Index startRow, Index n) const
 
template<int N>
NRowsBlockXpr< N >::Type middleRows (Index startRow, Index n=N)
 
template<int N>
ConstNRowsBlockXpr< N >::Type middleRows (Index startRow, Index n=N) const
 
Index nonZeros () const
 
const ScalarMultipleReturnType operator* (const Scalar &scalar) const
 
const CwiseUnaryOp
< internal::scalar_multiple2_op
< Scalar, std::complex< Scalar >
>, const Derived > 		operator* (const std::complex< Scalar > &scalar) const
 
template<typename OtherDerived >
const
SparseSparseProductReturnType
< Derived, OtherDerived >
::Type 		operator* (const SparseMatrixBase< OtherDerived > &other) const
 
template<typename OtherDerived >
const
SparseDenseProductReturnType
< Derived, OtherDerived >
::Type 		operator* (const MatrixBase< OtherDerived > &other) const
 
template<typename OtherDerived >
const CwiseBinaryOp
< internal::scalar_sum_op
< Scalar >, const Derived,
const OtherDerived > 		operator+ (const Eigen::SparseMatrixBase< OtherDerived > &other) const
 
template<typename OtherDerived >
const CwiseBinaryOp
< internal::scalar_difference_op
< Scalar >, const Derived,
const OtherDerived > 		operator- (const Eigen::SparseMatrixBase< OtherDerived > &other) const
 
const CwiseUnaryOp
< internal::scalar_opposite_op
< typename internal::traits
< Derived >::Scalar >, const
Derived > 		operator- () const
 
const CwiseUnaryOp
< internal::scalar_quotient1_op
< typename internal::traits
< Derived >::Scalar >, const
Derived > 		operator/ (const Scalar &scalar) const
 
Index outerSize () const
 
RealReturnType real () const
 
NonConstRealReturnType real ()
 
ColsBlockXpr rightCols (Index n)
 
ConstColsBlockXpr rightCols (Index n) const
 
template<int N>
NColsBlockXpr< N >::Type rightCols (Index n=N)
 
template<int N>
ConstNColsBlockXpr< N >::Type rightCols (Index n=N) const
 
RowXpr row (Index i)
 
ConstRowXpr row (Index i) const
 
Index rows () const
 
SegmentReturnType segment (Index start, Index n)
 
ConstSegmentReturnType segment (Index start, Index n) const
 
template<int N>
FixedSegmentReturnType< N >::Type segment (Index start, Index n=N)
 
template<int N>
ConstFixedSegmentReturnType< N >
::Type 		segment (Index start, Index n=N) const
 
Index size () const
 
SegmentReturnType tail (Index n)
 
ConstSegmentReturnType tail (Index n) const
 
template<int N>
FixedSegmentReturnType< N >::Type tail (Index n=N)
 
template<int N>
ConstFixedSegmentReturnType< N >
::Type 		tail (Index n=N) const
 
Block< Derived > topLeftCorner (Index cRows, Index cCols)
 
const Block< const Derived > topLeftCorner (Index cRows, Index cCols) const
 
template<int CRows, int CCols>
Block< Derived, CRows, CCols > topLeftCorner ()
 
template<int CRows, int CCols>
const Block< const Derived,
CRows, CCols > 		topLeftCorner () const
 
template<int CRows, int CCols>
Block< Derived, CRows, CCols > topLeftCorner (Index cRows, Index cCols)
 
template<int CRows, int CCols>
const Block< const Derived,
CRows, CCols > 		topLeftCorner (Index cRows, Index cCols) const
 
Block< Derived > topRightCorner (Index cRows, Index cCols)
 
const Block< const Derived > topRightCorner (Index cRows, Index cCols) const
 
template<int CRows, int CCols>
Block< Derived, CRows, CCols > topRightCorner ()
 
template<int CRows, int CCols>
const Block< const Derived,
CRows, CCols > 		topRightCorner () const
 
template<int CRows, int CCols>
Block< Derived, CRows, CCols > topRightCorner (Index cRows, Index cCols)
 
template<int CRows, int CCols>
const Block< const Derived,
CRows, CCols > 		topRightCorner (Index cRows, Index cCols) const
 
RowsBlockXpr topRows (Index n)
 
ConstRowsBlockXpr topRows (Index n) const
 
template<int N>
NRowsBlockXpr< N >::Type topRows (Index n=N)
 
template<int N>
ConstNRowsBlockXpr< N >::Type topRows (Index n=N) const
 
SparseSymmetricPermutationProduct
< Derived, Upper|Lower > 		twistedBy (const PermutationMatrix< Dynamic, Dynamic, Index > &perm) const
 
template<typename CustomUnaryOp >
const CwiseUnaryOp
< CustomUnaryOp, const Derived > 		unaryExpr (const CustomUnaryOp &func=CustomUnaryOp()) const
 Apply a unary operator coefficient-wise. More...
 
template<typename CustomViewOp >
const CwiseUnaryView
< CustomViewOp, const Derived > 		unaryViewExpr (const CustomViewOp &func=CustomViewOp()) const
 

Friends

template<typename OtherDerived >
const
DenseSparseProductReturnType
< OtherDerived, Derived >
::Type 		operator* (const MatrixBase< OtherDerived > &lhs, const Derived &rhs)
 

Member Enumeration Documentation

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).

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.

CoeffReadCost 

This is a rough measure of how expensive it is to read one coefficient from this expression.

Member Function Documentation

const CwiseBinaryOp<CustomBinaryOp, const Derived, const OtherDerived> binaryExpr ( const Eigen::SparseMatrixBase< OtherDerived > &  other,
const CustomBinaryOp &  func = CustomBinaryOp() 
) const
inline
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()
Block<Derived> block ( Index  startRow,
Index  startCol,
Index  blockRows,
Index  blockCols 
)
inline
Returns
a dynamic-size expression of a block in *this.
Parameters
startRowthe first row in the block
startColthe first column in the block
blockRowsthe number of rows in the block
blockColsthe number of columns in the block

Example:

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;

Output: 

Here is the matrix m:
 7  9 -5 -3
-2 -6  1  0
 6 -3  0  9
 6  6  3  9
Here is m.block(1, 1, 2, 2):
-6  1
-3  0
Now the matrix m is:
 7  9 -5 -3
-2  0  0  0
 6  0  0  9
 6  6  3  9
Note
Even though 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.
See Also
class Block, block(Index,Index)
const Block<const Derived> block ( Index  startRow,
Index  startCol,
Index  blockRows,
Index  blockCols 
) const
inline

This is the const version of block(Index,Index,Index,Index).

Block<Derived, BlockRows, BlockCols> block ( Index  startRow,
Index  startCol 
)
inline
Returns
a fixed-size expression of a block in *this.

The template parameters BlockRows and BlockCols are the number of rows and columns in the block.

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

Example:

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;

Output: 

Here is the matrix m:
 7  9 -5 -3
-2 -6  1  0
 6 -3  0  9
 6  6  3  9
Here is m.block<2,2>(1,1):
-6  1
-3  0
Now the matrix m is:
 7  9 -5 -3
-2  0  0  0
 6  0  0  9
 6  6  3  9
Note
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);
See Also
class Block, block(Index,Index,Index,Index)
const Block<const Derived, BlockRows, BlockCols> block ( Index  startRow,
Index  startCol 
) const
inline

This is the const version of block<>(Index, Index).

Block<Derived, BlockRows, BlockCols> block ( Index  startRow,
Index  startCol,
Index  blockRows,
Index  blockCols 
)
inline
Returns
an expression of a block in *this.
Template Parameters
BlockRowsnumber of rows in block as specified at compile-time
BlockColsnumber 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 BlockRows unless BlockRows is Dynamic, and the same for the number of columns.

Example:

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: 

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;
See Also
class Block, block(Index,Index,Index,Index)
const Block<const Derived, BlockRows, BlockCols> block ( Index  startRow,
Index  startCol,
Index  blockRows,
Index  blockCols 
) const
inline

This is the const version of block<>(Index, Index, Index, Index).

Block<Derived> bottomLeftCorner ( Index  cRows,
Index  cCols 
)
inline
Returns
a dynamic-size expression of a bottom-left corner of *this.
Parameters
cRowsthe number of rows in the corner
cColsthe number of columns in the corner

Example:

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:
 7  9 -5 -3
-2 -6  1  0
 6 -3  0  9
 6  6  3  9
Here is m.bottomLeftCorner(2, 2):
 6 -3
 6  6
Now the matrix m is:
 7  9 -5 -3
-2 -6  1  0
 0  0  0  9
 0  0  3  9
See Also
class Block, block(Index,Index,Index,Index)
const Block<const Derived> bottomLeftCorner ( Index  cRows,
Index  cCols 
) const
inline

This is the const version of bottomLeftCorner(Index, Index).

Block<Derived, CRows, CCols> bottomLeftCorner ( )
inline
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:

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:
 7  9 -5 -3
-2 -6  1  0
 6 -3  0  9
 6  6  3  9
Here is m.bottomLeftCorner<2,2>():
 6 -3
 6  6
Now the matrix m is:
 7  9 -5 -3
-2 -6  1  0
 0  0  0  9
 0  0  3  9
See Also
class Block, block(Index,Index,Index,Index)
const Block<const Derived, CRows, CCols> bottomLeftCorner ( ) const
inline

This is the const version of bottomLeftCorner<int, int>().

Block<Derived, CRows, CCols> 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:

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:
 7  9 -5 -3
-2 -6  1  0
 6 -3  0  9
 6  6  3  9
Here is m.bottomLeftCorner<2,Dynamic>(2,2):
 6 -3
 6  6
Now the matrix m is:
 7  9 -5 -3
-2 -6  1  0
 0  0  0  9
 0  0  3  9
See Also
class Block
const Block<const Derived, CRows, CCols> bottomLeftCorner ( Index  cRows,
Index  cCols 
) const
inline

This is the const version of bottomLeftCorner<int, int>(Index, Index).

Block<Derived> bottomRightCorner ( Index  cRows,
Index  cCols 
)
inline
Returns
a dynamic-size expression of a bottom-right corner of *this.
Parameters
cRowsthe number of rows in the corner
cColsthe number of columns in the corner

Example:

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:
 7  9 -5 -3
-2 -6  1  0
 6 -3  0  9
 6  6  3  9
Here is m.bottomRightCorner(2, 2):
0 9
3 9
Now the matrix m is:
 7  9 -5 -3
-2 -6  1  0
 6 -3  0  0
 6  6  0  0
See Also
class Block, block(Index,Index,Index,Index)
const Block<const Derived> bottomRightCorner ( Index  cRows,
Index  cCols 
) const
inline

This is the const version of bottomRightCorner(Index, Index).

Block<Derived, CRows, CCols> bottomRightCorner ( )
inline
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:

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:
 7  9 -5 -3
-2 -6  1  0
 6 -3  0  9
 6  6  3  9
Here is m.bottomRightCorner<2,2>():
0 9
3 9
Now the matrix m is:
 7  9 -5 -3
-2 -6  1  0
 6 -3  0  0
 6  6  0  0
See Also
class Block, block(Index,Index,Index,Index)
const Block<const Derived, CRows, CCols> bottomRightCorner ( ) const
inline

This is the const version of bottomRightCorner<int, int>().

Block<Derived, CRows, CCols> bottomRightCorner ( Index  cRows,
Index  cCols 
)
inline
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:

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:
 7  9 -5 -3
-2 -6  1  0
 6 -3  0  9
 6  6  3  9
Here is m.bottomRightCorner<2,Dynamic>(2,2):
0 9
3 9
Now the matrix m is:
 7  9 -5 -3
-2 -6  1  0
 6 -3  0  0
 6  6  0  0
See Also
class Block
const Block<const Derived, CRows, CCols> bottomRightCorner ( Index  cRows,
Index  cCols 
) const
inline

This is the const version of bottomRightCorner<int, int>(Index, Index).

RowsBlockXpr bottomRows ( Index  n)
inline
Returns
a block consisting of the bottom rows of *this.
Parameters
nthe number of rows in the block

Example:

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:
 7  9 -5 -3
-2 -6  1  0
 6 -3  0  9
 6  6  3  9
Here is a.bottomRows(2):
 6 -3  0  9
 6  6  3  9
Now the array a is:
 7  9 -5 -3
-2 -6  1  0
 0  0  0  0
 0  0  0  0
See Also
class Block, block(Index,Index,Index,Index)
ConstRowsBlockXpr bottomRows ( Index  n) const
inline

This is the const version of bottomRows(Index).

NRowsBlockXpr<N>::Type bottomRows ( Index  n = N)
inline
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:

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:
 7  9 -5 -3
-2 -6  1  0
 6 -3  0  9
 6  6  3  9
Here is a.bottomRows<2>():
 6 -3  0  9
 6  6  3  9
Now the array a is:
 7  9 -5 -3
-2 -6  1  0
 0  0  0  0
 0  0  0  0
See Also
class Block, block(Index,Index,Index,Index)
ConstNRowsBlockXpr<N>::Type bottomRows ( Index  n = N) const
inline

This is the const version of bottomRows<int>().

internal::cast_return_type<Derived,const CwiseUnaryOp<internal::scalar_cast_op<typename internal::traits<Derived>::Scalar, NewType>, const Derived> >::type cast ( ) const
inline
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
ColXpr col ( Index  i)
inline
Returns
an expression of the i-th column of *this. Note that the numbering starts at 0.

Example:

Matrix3d m = Matrix3d::Identity();
m.col(1) = Vector3d(4,5,6);
cout << m << endl;

Output: 

1 4 0
0 5 0
0 6 1
See Also
row(), class Block

Referenced by SparseMatrixBase< CwiseBinaryOp< BinaryOp, Lhs, Rhs > >::bottomRightCorner().

ConstColXpr col ( Index  i) const
inline

This is the const version of col().

Index cols ( void  ) const
inline
Returns
the number of columns.
See Also
rows()

Referenced by SparseMatrixBase< CwiseBinaryOp< BinaryOp, Lhs, Rhs > >::isVector(), SparseMatrixBase< CwiseBinaryOp< BinaryOp, Lhs, Rhs > >::outerSize(), SparseMatrixBase< CwiseBinaryOp< BinaryOp, Lhs, Rhs > >::size(), and SparseMatrixBase< CwiseBinaryOp< BinaryOp, Lhs, Rhs > >::topLeftCorner().

ConjugateReturnType conjugate ( ) const
inline
Returns
an expression of the complex conjugate of *this.
See Also
adjoint()
const CwiseUnaryOp<internal::scalar_abs_op<Scalar>, const Derived> cwiseAbs ( ) const
inline
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()
const CwiseUnaryOp<internal::scalar_abs2_op<Scalar>, const Derived> cwiseAbs2 ( ) const
inline
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()
const CwiseBinaryOp<std::equal_to<Scalar>, const Derived, const OtherDerived> cwiseEqual ( const Eigen::SparseMatrixBase< OtherDerived > &  other) const
inline
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()
const CwiseScalarEqualReturnType cwiseEqual ( const Scalar &  s) const
inline
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
const CwiseUnaryOp<internal::scalar_inverse_op<Scalar>, const Derived> cwiseInverse ( ) const
inline
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()
const CwiseBinaryOp<internal::scalar_max_op<Scalar>, const Derived, const OtherDerived> cwiseMax ( const Eigen::SparseMatrixBase< OtherDerived > &  other) const
inline
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()
const CwiseBinaryOp<internal::scalar_max_op<Scalar>, const Derived, const ConstantReturnType> cwiseMax ( const Scalar &  other) const
inline
Returns
an expression of the coefficient-wise max of *this and scalar other
See Also
class CwiseBinaryOp, min()
const CwiseBinaryOp<internal::scalar_min_op<Scalar>, const Derived, const OtherDerived> cwiseMin ( const Eigen::SparseMatrixBase< OtherDerived > &  other) const
inline
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()
const CwiseBinaryOp<internal::scalar_min_op<Scalar>, const Derived, const ConstantReturnType> cwiseMin ( const Scalar &  other) const
inline
Returns
an expression of the coefficient-wise min of *this and scalar other
See Also
class CwiseBinaryOp, min()
const CwiseBinaryOp<std::not_equal_to<Scalar>, const Derived, const OtherDerived> cwiseNotEqual ( const Eigen::SparseMatrixBase< OtherDerived > &  other) const
inline
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()
const CwiseBinaryOp<internal::scalar_product_op<typename Derived ::Scalar, typename OtherDerived ::Scalar >, const Derived , const OtherDerived > cwiseProduct ( const Eigen::SparseMatrixBase< OtherDerived > &  other) const
inline
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
const CwiseBinaryOp<internal::scalar_quotient_op<Scalar>, const Derived, const OtherDerived> cwiseQuotient ( const Eigen::SparseMatrixBase< OtherDerived > &  other) const
inline
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()
const CwiseUnaryOp<internal::scalar_sqrt_op<Scalar>, const Derived> cwiseSqrt ( ) const
inline
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& derived ( )
inlineinherited
Returns
a reference to the derived object

Referenced by IterativeSolverBase< ConjugateGradient< _MatrixType, _UpLo, _Preconditioner > >::analyzePattern(), MatrixBase< Derived >::applyOnTheLeft(), MatrixBase< Derived >::applyOnTheRight(), PermutationBase< PermutationMatrix< SizeAtCompileTime, MaxSizeAtCompileTime, IndexType > >::applyTranspositionOnTheLeft(), PermutationBase< PermutationMatrix< SizeAtCompileTime, MaxSizeAtCompileTime, IndexType > >::applyTranspositionOnTheRight(), SparseMatrixBase< CwiseBinaryOp< BinaryOp, Lhs, Rhs > >::bottomRows(), EigenBase< SparseSymmetricPermutationProduct< MatrixType, UpLo > >::cols(), SparseMatrixBase< CwiseBinaryOp< BinaryOp, Lhs, Rhs > >::cols(), IterativeSolverBase< ConjugateGradient< _MatrixType, _UpLo, _Preconditioner > >::compute(), SparseMatrixBase< CwiseBinaryOp< BinaryOp, Lhs, Rhs > >::eval(), IterativeSolverBase< ConjugateGradient< _MatrixType, _UpLo, _Preconditioner > >::factorize(), PermutationBase< PermutationMatrix< SizeAtCompileTime, MaxSizeAtCompileTime, IndexType > >::indices(), PermutationBase< PermutationMatrix< SizeAtCompileTime, MaxSizeAtCompileTime, IndexType > >::inverse(), IterativeSolverBase< ConjugateGradient< _MatrixType, _UpLo, _Preconditioner > >::IterativeSolverBase(), RotationBase< Derived, 3 >::operator*(), SparseSelfAdjointView< MatrixType, UpLo >::operator*(), PermutationBase< PermutationMatrix< SizeAtCompileTime, MaxSizeAtCompileTime, IndexType > >::operator*(), SparseMatrixBase< Derived >::operator*(), SparseMatrixBase< CwiseBinaryOp< BinaryOp, Lhs, Rhs > >::operator*(), Transform< Scalar, Dim, Mode, _Options >::operator*(), Eigen::operator*(), MatrixBase< Derived >::operator*=(), PermutationBase< PermutationMatrix< SizeAtCompileTime, MaxSizeAtCompileTime, IndexType > >::operator=(), DenseBase< Derived >::operator=(), Transform< Scalar, Dim, Mode, _Options >::operator=(), PlainObjectBase< Matrix< _Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols > >::operator=(), PlainObjectBase< Matrix< _Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols > >::PlainObjectBase(), SparseMatrixBase< CwiseBinaryOp< BinaryOp, Lhs, Rhs > >::real(), PlainObjectBase< Matrix< _Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols > >::resizeLike(), EigenBase< SparseSymmetricPermutationProduct< MatrixType, UpLo > >::rows(), SparseMatrixBase< CwiseBinaryOp< BinaryOp, Lhs, Rhs > >::rows(), SimplicialCholeskyBase< SimplicialLDLT< _MatrixType, _UpLo, _Ordering > >::solve(), IterativeSolverBase< ConjugateGradient< _MatrixType, _UpLo, _Preconditioner > >::solve(), SparseLU< _MatrixType, _OrderingType >::solve(), UmfPackLU< _MatrixType >::solve(), CholmodBase< _MatrixType, _UpLo, CholmodSimplicialLLT< _MatrixType, _UpLo > >::solve(), SuperLUBase< _MatrixType, SuperILU< _MatrixType > >::solve(), SparseMatrix< Scalar, RowMajor >::SparseMatrix(), PermutationBase< PermutationMatrix< SizeAtCompileTime, MaxSizeAtCompileTime, IndexType > >::toDenseMatrix(), SparseMatrixBase< CwiseBinaryOp< BinaryOp, Lhs, Rhs > >::topLeftCorner(), Transform< Scalar, Dim, Mode, _Options >::Transform(), PermutationBase< PermutationMatrix< SizeAtCompileTime, MaxSizeAtCompileTime, IndexType > >::transpose(), and SparseMatrixBase< CwiseBinaryOp< BinaryOp, Lhs, Rhs > >::twistedBy().

const Derived& derived ( ) const
inlineinherited
Returns
a const reference to the derived object
const internal::eval<Derived>::type 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.

SegmentReturnType head ( Index  n)
inline
Returns
a dynamic-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.

Parameters
nthe number of coefficients in the segment

Example:

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:
 7 -2  6  6
Here is v.head(2):
 7 -2
Now the vector v is:
0 0 6 6
Note
Even though 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)
ConstSegmentReturnType head ( Index  n) const
inline

This is the const version of head(Index).

FixedSegmentReturnType<N>::Type head ( Index  n = N)
inline
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:

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:
 7 -2  6  6
Here is v.head(2):
 7 -2
Now the vector v is:
0 0 6 6
See Also
class Block
ConstFixedSegmentReturnType<N>::Type head ( Index  n = N) const
inline

This is the const version of head<int>().

const ImagReturnType imag ( ) const
inline
Returns
an read-only expression of the imaginary part of *this.
See Also
real()
NonConstImagReturnType imag ( )
inline
Returns
a non const expression of the imaginary part of *this.
See Also
real()
Index innerSize ( ) const
inline
Returns
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
SparseMatrixBase< Derived >::InnerVectorReturnType innerVector ( Index  outer)
Returns
the outer -th column (resp. row) of the matrix *this if *this is col-major (resp. row-major).
const SparseMatrixBase< Derived >::ConstInnerVectorReturnType innerVector ( Index  outer) const
Returns
the outer -th column (resp. row) of the matrix *this if *this is col-major (resp. row-major). Read-only.
SparseMatrixBase< Derived >::InnerVectorsReturnType innerVectors ( Index  outerStart,
Index  outerSize 
)
Returns
the outer -th column (resp. row) of the matrix *this if *this is col-major (resp. row-major).
const SparseMatrixBase< Derived >::ConstInnerVectorsReturnType innerVectors ( Index  outerStart,
Index  outerSize 
) const
Returns
the outer -th column (resp. row) of the matrix *this if *this is col-major (resp. row-major). Read-only.
bool 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.
ColsBlockXpr leftCols ( Index  n)
inline
Returns
a block consisting of the left columns of *this.
Parameters
nthe number of columns in the block

Example:

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:
 7  9 -5 -3
-2 -6  1  0
 6 -3  0  9
 6  6  3  9
Here is a.leftCols(2):
 7  9
-2 -6
 6 -3
 6  6
Now the array a is:
 0  0 -5 -3
 0  0  1  0
 0  0  0  9
 0  0  3  9
See Also
class Block, block(Index,Index,Index,Index)
ConstColsBlockXpr leftCols ( Index  n) const
inline

This is the const version of leftCols(Index).

NColsBlockXpr<N>::Type leftCols ( Index  n = N)
inline
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:

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:
 7  9 -5 -3
-2 -6  1  0
 6 -3  0  9
 6  6  3  9
Here is a.leftCols<2>():
 7  9
-2 -6
 6 -3
 6  6
Now the array a is:
 0  0 -5 -3
 0  0  1  0
 0  0  0  9
 0  0  3  9
See Also
class Block, block(Index,Index,Index,Index)
ConstNColsBlockXpr<N>::Type leftCols ( Index  n = N) const
inline

This is the const version of leftCols<int>().

ColsBlockXpr middleCols ( Index  startCol,
Index  numCols 
)
inline
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

Example:

#include <Eigen/Core>
#include <iostream>
using namespace Eigen;
using namespace std;
int main(void)
{
int const N = 5;
MatrixXi A(N,N);
A.setRandom();
cout << "A =\n" << A << '\n' << endl;
cout << "A(1..3,:) =\n" << A.middleCols(1,3) << endl;
return 0;
}

Output: 

A =
  7  -6   0   9 -10
 -2  -3   3   3  -5
  6   6  -3   5  -8
  6  -5   0  -8   6
  9   1   9   2  -7

A(1..3,:) =
-6  0  9
-3  3  3
 6 -3  5
-5  0 -8
 1  9  2
See Also
class Block, block(Index,Index,Index,Index)
ConstColsBlockXpr middleCols ( Index  startCol,
Index  numCols 
) const
inline

This is the const version of middleCols(Index,Index).

NColsBlockXpr<N>::Type middleCols ( Index  startCol,
Index  n = N 
)
inline
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:

#include <Eigen/Core>
#include <iostream>
using namespace Eigen;
using namespace std;
int main(void)
{
int const N = 5;
MatrixXi A(N,N);
A.setRandom();
cout << "A =\n" << A << '\n' << endl;
cout << "A(:,1..3) =\n" << A.middleCols<3>(1) << endl;
return 0;
}

Output: 

A =
  7  -6   0   9 -10
 -2  -3   3   3  -5
  6   6  -3   5  -8
  6  -5   0  -8   6
  9   1   9   2  -7

A(:,1..3) =
-6  0  9
-3  3  3
 6 -3  5
-5  0 -8
 1  9  2
See Also
class Block, block(Index,Index,Index,Index)
ConstNColsBlockXpr<N>::Type middleCols ( Index  startCol,
Index  n = N 
) const
inline

This is the const version of middleCols<int>().

RowsBlockXpr middleRows ( Index  startRow,
Index  n 
)
inline
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

Example:

#include <Eigen/Core>
#include <iostream>
using namespace Eigen;
using namespace std;
int main(void)
{
int const N = 5;
MatrixXi A(N,N);
A.setRandom();
cout << "A =\n" << A << '\n' << endl;
cout << "A(2..3,:) =\n" << A.middleRows(2,2) << endl;
return 0;
}

Output: 

A =
  7  -6   0   9 -10
 -2  -3   3   3  -5
  6   6  -3   5  -8
  6  -5   0  -8   6
  9   1   9   2  -7

A(2..3,:) =
 6  6 -3  5 -8
 6 -5  0 -8  6
See Also
class Block, block(Index,Index,Index,Index)
ConstRowsBlockXpr middleRows ( Index  startRow,
Index  n 
) const
inline

This is the const version of middleRows(Index,Index).

NRowsBlockXpr<N>::Type middleRows ( Index  startRow,
Index  n = N 
)
inline
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:

#include <Eigen/Core>
#include <iostream>
using namespace Eigen;
using namespace std;
int main(void)
{
int const N = 5;
MatrixXi A(N,N);
A.setRandom();
cout << "A =\n" << A << '\n' << endl;
cout << "A(1..3,:) =\n" << A.middleRows<3>(1) << endl;
return 0;
}

Output: 

A =
  7  -6   0   9 -10
 -2  -3   3   3  -5
  6   6  -3   5  -8
  6  -5   0  -8   6
  9   1   9   2  -7

A(1..3,:) =
-2 -3  3  3 -5
 6  6 -3  5 -8
 6 -5  0 -8  6
See Also
class Block, block(Index,Index,Index,Index)
ConstNRowsBlockXpr<N>::Type middleRows ( Index  startRow,
Index  n = N 
) const
inline

This is the const version of middleRows<int>().

Index nonZeros ( ) const
inline
Returns
the number of nonzero coefficients which is in practice the number of stored coefficients.
const ScalarMultipleReturnType operator* ( const Scalar &  scalar) const
inline
Returns
an expression of *this scaled by the scalar factor scalar
const CwiseUnaryOp<internal::scalar_multiple2_op<Scalar,std::complex<Scalar> >, const Derived> operator* ( const std::complex< Scalar > &  scalar) const
inline

Overloaded for efficient real matrix times complex scalar value

const SparseSparseProductReturnType< Derived, OtherDerived >::Type 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(); // supress numerical zeros (exact)
* C = (A*B).pruned(ref);
* C = (A*B).pruned(ref,epsilon);
*
where ref is a meaningful non zero reference value.

References EigenBase< Derived >::derived().

const SparseDenseProductReturnType<Derived,OtherDerived>::Type operator* ( const MatrixBase< OtherDerived > &  other) const
inline

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

const CwiseBinaryOp< internal::scalar_sum_op <Scalar>, const Derived, const OtherDerived> 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+=()
const CwiseBinaryOp< internal::scalar_difference_op <Scalar>, const Derived, const OtherDerived> operator- ( const Eigen::SparseMatrixBase< OtherDerived > &  other) const
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-=()
const CwiseUnaryOp<internal::scalar_opposite_op<typename internal::traits<Derived>::Scalar>, const Derived> operator- ( ) const
inline
Returns
an expression of the opposite of *this
const CwiseUnaryOp<internal::scalar_quotient1_op<typename internal::traits<Derived>::Scalar>, const Derived> operator/ ( const Scalar &  scalar) const
inline
Returns
an expression of *this divided by the scalar value scalar
Index outerSize ( ) const
inline
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

Referenced by SparseMatrixBase< CwiseBinaryOp< BinaryOp, Lhs, Rhs > >::topLeftCorner().

RealReturnType real ( ) const
inline
Returns
a read-only expression of the real part of *this.
See Also
imag()
NonConstRealReturnType real ( )
inline
Returns
a non const expression of the real part of *this.
See Also
imag()
ColsBlockXpr rightCols ( Index  n)
inline
Returns
a block consisting of the right columns of *this.
Parameters
nthe number of columns in the block

Example:

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:
 7  9 -5 -3
-2 -6  1  0
 6 -3  0  9
 6  6  3  9
Here is a.rightCols(2):
-5 -3
 1  0
 0  9
 3  9
Now the array a is:
 7  9  0  0
-2 -6  0  0
 6 -3  0  0
 6  6  0  0
See Also
class Block, block(Index,Index,Index,Index)
ConstColsBlockXpr rightCols ( Index  n) const
inline

This is the const version of rightCols(Index).

NColsBlockXpr<N>::Type rightCols ( Index  n = N)
inline
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:

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:
 7  9 -5 -3
-2 -6  1  0
 6 -3  0  9
 6  6  3  9
Here is a.rightCols<2>():
-5 -3
 1  0
 0  9
 3  9
Now the array a is:
 7  9  0  0
-2 -6  0  0
 6 -3  0  0
 6  6  0  0
See Also
class Block, block(Index,Index,Index,Index)
ConstNColsBlockXpr<N>::Type rightCols ( Index  n = N) const
inline

This is the const version of rightCols<int>().

RowXpr row ( Index  i)
inline
Returns
an expression of the i-th row of *this. Note that the numbering starts at 0.

Example:

Matrix3d m = Matrix3d::Identity();
m.row(1) = Vector3d(4,5,6);
cout << m << endl;

Output: 

1 0 0
4 5 6
0 0 1
See Also
col(), class Block

Referenced by SparseMatrixBase< CwiseBinaryOp< BinaryOp, Lhs, Rhs > >::bottomRightCorner().

ConstRowXpr row ( Index  i) const
inline

This is the const version of row().

Index rows ( void  ) const
inline
Returns
the number of rows.
See Also
cols()

Referenced by SparseMatrixBase< CwiseBinaryOp< BinaryOp, Lhs, Rhs > >::isVector(), SparseMatrixBase< CwiseBinaryOp< BinaryOp, Lhs, Rhs > >::outerSize(), SparseMatrixBase< CwiseBinaryOp< BinaryOp, Lhs, Rhs > >::size(), SimplicialCholeskyBase< SimplicialLDLT< _MatrixType, _UpLo, _Ordering > >::solve(), IterativeSolverBase< ConjugateGradient< _MatrixType, _UpLo, _Preconditioner > >::solve(), SparseLU< _MatrixType, _OrderingType >::solve(), UmfPackLU< _MatrixType >::solve(), CholmodBase< _MatrixType, _UpLo, CholmodSimplicialLLT< _MatrixType, _UpLo > >::solve(), SuperLUBase< _MatrixType, SuperILU< _MatrixType > >::solve(), and SparseMatrixBase< CwiseBinaryOp< BinaryOp, Lhs, Rhs > >::topLeftCorner().

SegmentReturnType segment ( Index  start,
Index  n 
)
inline
Returns
a dynamic-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.

Parameters
startthe first coefficient in the segment
nthe number of coefficients in the segment

Example:

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:
 7 -2  6  6
Here is v.segment(1, 2):
-2  6
Now the vector v is:
7 0 0 6
Note
Even though 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, segment(Index)
ConstSegmentReturnType segment ( Index  start,
Index  n 
) const
inline

This is the const version of segment(Index,Index).

FixedSegmentReturnType<N>::Type segment ( Index  start,
Index  n = N 
)
inline
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:

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:
 7 -2  6  6
Here is v.segment<2>(1):
-2  6
Now the vector v is:
 7 -2  0  0
See Also
class Block
ConstFixedSegmentReturnType<N>::Type segment ( Index  start,
Index  n = N 
) const
inline

This is the const version of segment<int>(Index).

Index size ( ) const
inline
Returns
the number of coefficients, which is rows()*cols().
See Also
rows(), cols().
SegmentReturnType tail ( Index  n)
inline
Returns
a dynamic-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.

Parameters
nthe number of coefficients in the segment

Example:

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:
 7 -2  6  6
Here is v.tail(2):
6 6
Now the vector v is:
 7 -2  0  0
Note
Even though 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)
ConstSegmentReturnType tail ( Index  n) const
inline

This is the const version of tail(Index).

FixedSegmentReturnType<N>::Type tail ( Index  n = N)
inline
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:

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:
 7 -2  6  6
Here is v.tail(2):
6 6
Now the vector v is:
 7 -2  0  0
See Also
class Block
ConstFixedSegmentReturnType<N>::Type tail ( Index  n = N) const
inline

This is the const version of tail<int>.

Block<Derived> topLeftCorner ( Index  cRows,
Index  cCols 
)
inline
Returns
a dynamic-size expression of a top-left corner of *this.
Parameters
cRowsthe number of rows in the corner
cColsthe number of columns in the corner

Example:

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:
 7  9 -5 -3
-2 -6  1  0
 6 -3  0  9
 6  6  3  9
Here is m.topLeftCorner(2, 2):
 7  9
-2 -6
Now the matrix m is:
 0  0 -5 -3
 0  0  1  0
 6 -3  0  9
 6  6  3  9
See Also
class Block, block(Index,Index,Index,Index)
const Block<const Derived> topLeftCorner ( Index  cRows,
Index  cCols 
) const
inline

This is the const version of topLeftCorner(Index, Index).

Block<Derived, CRows, CCols> topLeftCorner ( )
inline
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:

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:
 7  9 -5 -3
-2 -6  1  0
 6 -3  0  9
 6  6  3  9
Here is m.topLeftCorner<2,2>():
 7  9
-2 -6
Now the matrix m is:
 0  0 -5 -3
 0  0  1  0
 6 -3  0  9
 6  6  3  9
See Also
class Block, block(Index,Index,Index,Index)
const Block<const Derived, CRows, CCols> topLeftCorner ( ) const
inline

This is the const version of topLeftCorner<int, int>().

Block<Derived, CRows, CCols> topLeftCorner ( Index  cRows,
Index  cCols 
)
inline
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:

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:
 7  9 -5 -3
-2 -6  1  0
 6 -3  0  9
 6  6  3  9
Here is m.topLeftCorner<2,Dynamic>(2,2):
 7  9
-2 -6
Now the matrix m is:
 0  0 -5 -3
 0  0  1  0
 6 -3  0  9
 6  6  3  9
See Also
class Block
const Block<const Derived, CRows, CCols> topLeftCorner ( Index  cRows,
Index  cCols 
) const
inline

This is the const version of topLeftCorner<int, int>(Index, Index).

Block<Derived> topRightCorner ( Index  cRows,
Index  cCols 
)
inline
Returns
a dynamic-size expression of a top-right corner of *this.
Parameters
cRowsthe number of rows in the corner
cColsthe number of columns in the corner

Example:

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:
 7  9 -5 -3
-2 -6  1  0
 6 -3  0  9
 6  6  3  9
Here is m.topRightCorner(2, 2):
-5 -3
 1  0
Now the matrix m is:
 7  9  0  0
-2 -6  0  0
 6 -3  0  9
 6  6  3  9
See Also
class Block, block(Index,Index,Index,Index)
const Block<const Derived> topRightCorner ( Index  cRows,
Index  cCols 
) const
inline

This is the const version of topRightCorner(Index, Index).

Block<Derived, CRows, CCols> topRightCorner ( )
inline
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:

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:
 7  9 -5 -3
-2 -6  1  0
 6 -3  0  9
 6  6  3  9
Here is m.topRightCorner<2,2>():
-5 -3
 1  0
Now the matrix m is:
 7  9  0  0
-2 -6  0  0
 6 -3  0  9
 6  6  3  9
See Also
class Block, block<int,int>(Index,Index)
const Block<const Derived, CRows, CCols> topRightCorner ( ) const
inline

This is the const version of topRightCorner<int, int>().

Block<Derived, CRows, CCols> topRightCorner ( Index  cRows,
Index  cCols 
)
inline
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:

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:
 7  9 -5 -3
-2 -6  1  0
 6 -3  0  9
 6  6  3  9
Here is m.topRightCorner<2,Dynamic>(2,2):
-5 -3
 1  0
Now the matrix m is:
 7  9  0  0
-2 -6  0  0
 6 -3  0  9
 6  6  3  9
See Also
class Block
const Block<const Derived, CRows, CCols> topRightCorner ( Index  cRows,
Index  cCols 
) const
inline

This is the const version of topRightCorner<int, int>(Index, Index).

RowsBlockXpr topRows ( Index  n)
inline
Returns
a block consisting of the top rows of *this.
Parameters
nthe number of rows in the block

Example:

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:
 7  9 -5 -3
-2 -6  1  0
 6 -3  0  9
 6  6  3  9
Here is a.topRows(2):
 7  9 -5 -3
-2 -6  1  0
Now the array a is:
 0  0  0  0
 0  0  0  0
 6 -3  0  9
 6  6  3  9
See Also
class Block, block(Index,Index,Index,Index)
ConstRowsBlockXpr topRows ( Index  n) const
inline

This is the const version of topRows(Index).

NRowsBlockXpr<N>::Type topRows ( Index  n = N)
inline
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:

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:
 7  9 -5 -3
-2 -6  1  0
 6 -3  0  9
 6  6  3  9
Here is a.topRows<2>():
 7  9 -5 -3
-2 -6  1  0
Now the array a is:
 0  0  0  0
 0  0  0  0
 6 -3  0  9
 6  6  3  9
See Also
class Block, block(Index,Index,Index,Index)
ConstNRowsBlockXpr<N>::Type topRows ( Index  n = N) const
inline

This is the const version of topRows<int>().

SparseSymmetricPermutationProduct<Derived,Upper|Lower> twistedBy ( const PermutationMatrix< Dynamic, Dynamic, Index > &  perm) const
inline
Returns
an expression of P H P^-1 where H is the matrix represented by *this
const CwiseUnaryOp<CustomUnaryOp, const Derived> unaryExpr ( const CustomUnaryOp &  func = CustomUnaryOp()) const
inline

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

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
const CwiseUnaryView<CustomViewOp, const Derived> unaryViewExpr ( const CustomViewOp &  func = CustomViewOp()) const
inline
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

Friends And Related Function Documentation

const DenseSparseProductReturnType<OtherDerived,Derived>::Type operator* ( const MatrixBase< OtherDerived > &  lhs,
const Derived &  rhs 
)
friend

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

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