Eigen  3.3.3
Eigen::SparseMatrixBase< Derived > Class Template Reference

Detailed Description

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

Base class of any sparse matrices or sparse expressions.

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

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

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

List of all members.

Public Types

enum  {
  RowsAtCompileTime,
  ColsAtCompileTime,
  SizeAtCompileTime ,
  IsVectorAtCompileTime,
  Flags
}
typedef internal::traits
< Derived >::StorageIndex 
StorageIndex
typedef Scalar value_type

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
BlockXpr block (Index startRow, Index startCol, Index blockRows, Index blockCols)
const ConstBlockXpr block (Index startRow, Index startCol, Index blockRows, Index blockCols) const
 This is the const version of block(Index,Index,Index,Index). */.
template<int NRows, int NCols>
FixedBlockXpr< NRows, NCols >::Type block (Index startRow, Index startCol)
template<int NRows, int NCols>
const ConstFixedBlockXpr
< NRows, NCols >::Type 
block (Index startRow, Index startCol) const
 This is the const version of block<>(Index, Index). */.
template<int NRows, int NCols>
FixedBlockXpr< NRows, NCols >::Type block (Index startRow, Index startCol, Index blockRows, Index blockCols)
template<int NRows, int NCols>
const ConstFixedBlockXpr
< NRows, NCols >::Type 
block (Index startRow, Index startCol, Index blockRows, Index blockCols) const
 This is the const version of block<>(Index, Index, Index, Index).
BlockXpr bottomLeftCorner (Index cRows, Index cCols)
const ConstBlockXpr bottomLeftCorner (Index cRows, Index cCols) const
 This is the const version of bottomLeftCorner(Index, Index).
template<int CRows, int CCols>
FixedBlockXpr< CRows, CCols >::Type bottomLeftCorner ()
template<int CRows, int CCols>
const ConstFixedBlockXpr
< CRows, CCols >::Type 
bottomLeftCorner () const
 This is the const version of bottomLeftCorner<int, int>().
template<int CRows, int CCols>
FixedBlockXpr< CRows, CCols >::Type bottomLeftCorner (Index cRows, Index cCols)
template<int CRows, int CCols>
const ConstFixedBlockXpr
< CRows, CCols >::Type 
bottomLeftCorner (Index cRows, Index cCols) const
 This is the const version of bottomLeftCorner<int, int>(Index, Index).
BlockXpr bottomRightCorner (Index cRows, Index cCols)
const ConstBlockXpr bottomRightCorner (Index cRows, Index cCols) const
 This is the const version of bottomRightCorner(Index, Index).
template<int CRows, int CCols>
FixedBlockXpr< CRows, CCols >::Type bottomRightCorner ()
template<int CRows, int CCols>
const ConstFixedBlockXpr
< CRows, CCols >::Type 
bottomRightCorner () const
 This is the const version of bottomRightCorner<int, int>().
template<int CRows, int CCols>
FixedBlockXpr< CRows, CCols >::Type bottomRightCorner (Index cRows, Index cCols)
template<int CRows, int CCols>
const ConstFixedBlockXpr
< CRows, CCols >::Type 
bottomRightCorner (Index cRows, Index cCols) const
 This is the const version of bottomRightCorner<int, int>(Index, Index).
RowsBlockXpr bottomRows (Index n)
ConstRowsBlockXpr bottomRows (Index n) const
 This is the const version of bottomRows(Index).
template<int N>
NRowsBlockXpr< N >::Type bottomRows (Index n=N)
template<int N>
ConstNRowsBlockXpr< N >::Type bottomRows (Index n=N) const
 This is the const version of bottomRows<int>().
template<typename NewType >
CastXpr< NewType >::Type cast () const
ColXpr col (Index i)
ConstColXpr col (Index i) const
 This is the const version of col().
Index cols () const
ConjugateReturnType conjugate () const
const CwiseAbsReturnType cwiseAbs () const
const CwiseAbs2ReturnType 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 CwiseInverseReturnType cwiseInverse () const
template<typename OtherDerived >
const CwiseBinaryOp
< internal::scalar_max_op
< Scalar, Scalar >, const
Derived, const OtherDerived > 
cwiseMax (const Eigen::SparseMatrixBase< OtherDerived > &other) const
const CwiseBinaryOp
< internal::scalar_max_op
< Scalar, Scalar >, const
Derived, const
ConstantReturnType > 
cwiseMax (const Scalar &other) const
template<typename OtherDerived >
const CwiseBinaryOp
< internal::scalar_min_op
< Scalar, Scalar >, const
Derived, const OtherDerived > 
cwiseMin (const Eigen::SparseMatrixBase< OtherDerived > &other) const
const CwiseBinaryOp
< internal::scalar_min_op
< Scalar, 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
< Derived::Scalar,
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 CwiseSignReturnType cwiseSign () const
const CwiseSqrtReturnType cwiseSqrt () const
const internal::eval< Derived >
::type 
eval () const
SegmentReturnType head (Index n)
ConstSegmentReturnType head (Index n) const
 This is the const version of head(Index).
template<int N>
FixedSegmentReturnType< N >::Type head (Index n=N)
template<int N>
ConstFixedSegmentReturnType< N >
::Type 
head (Index n=N) const
 This is the const version of head<int>().
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
 This is the const version of leftCols(Index).
template<int N>
NColsBlockXpr< N >::Type leftCols (Index n=N)
template<int N>
ConstNColsBlockXpr< N >::Type leftCols (Index n=N) const
 This is the const version of leftCols<int>().
ColsBlockXpr middleCols (Index startCol, Index numCols)
ConstColsBlockXpr middleCols (Index startCol, Index numCols) const
 This is the const version of middleCols(Index,Index).
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
 This is the const version of middleCols<int>().
RowsBlockXpr middleRows (Index startRow, Index n)
ConstRowsBlockXpr middleRows (Index startRow, Index n) const
 This is the const version of middleRows(Index,Index).
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
 This is the const version of middleRows<int>().
template<typename OtherDerived >
const CwiseBinaryOp
< internal::scalar_boolean_and_op,
const Derived, const
OtherDerived > 
operator&& (const Eigen::SparseMatrixBase< OtherDerived > &other) const
template<typename T >
const CwiseBinaryOp
< internal::scalar_product_op
< Scalar, T >, Derived,
Constant< T > > 
operator* (const T &scalar) const
template<typename OtherDerived >
const Product< Derived,
OtherDerived, AliasFreeProduct > 
operator* (const SparseMatrixBase< OtherDerived > &other) const
template<typename OtherDerived >
const CwiseBinaryOp< sum
< Scalar >, const Derived,
const OtherDerived > 
operator+ (const Eigen::SparseMatrixBase< OtherDerived > &other) const
template<typename OtherDerived >
const CwiseBinaryOp
< difference< Scalar >, const
Derived, const OtherDerived > 
operator- (const Eigen::SparseMatrixBase< OtherDerived > &other) const
const NegativeReturnType operator- () const
template<typename T >
const CwiseBinaryOp
< internal::scalar_quotient_op
< Scalar, T >, Derived,
Constant< T > > 
operator/ (const T &scalar) const
template<typename OtherDerived >
const CwiseBinaryOp
< internal::scalar_boolean_or_op,
const Derived, const
OtherDerived > 
operator|| (const Eigen::SparseMatrixBase< OtherDerived > &other) const
Index outerSize () const
const SparseView< Derived > pruned (const Scalar &reference=Scalar(0), const RealScalar &epsilon=NumTraits< Scalar >::dummy_precision()) const
RealReturnType real () const
NonConstRealReturnType real ()
ColsBlockXpr rightCols (Index n)
ConstColsBlockXpr rightCols (Index n) const
 This is the const version of rightCols(Index).
template<int N>
NColsBlockXpr< N >::Type rightCols (Index n=N)
template<int N>
ConstNColsBlockXpr< N >::Type rightCols (Index n=N) const
 This is the const version of rightCols<int>().
RowXpr row (Index i)
ConstRowXpr row (Index i) const
 This is the const version of row(). */.
Index rows () const
SegmentReturnType segment (Index start, Index n)
ConstSegmentReturnType segment (Index start, Index n) const
 This is the const version of segment(Index,Index).
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
 This is the const version of segment<int>(Index).
Index size () const
SegmentReturnType tail (Index n)
ConstSegmentReturnType tail (Index n) const
 This is the const version of tail(Index).
template<int N>
FixedSegmentReturnType< N >::Type tail (Index n=N)
template<int N>
ConstFixedSegmentReturnType< N >
::Type 
tail (Index n=N) const
 This is the const version of tail<int>.
BlockXpr topLeftCorner (Index cRows, Index cCols)
const ConstBlockXpr topLeftCorner (Index cRows, Index cCols) const
 This is the const version of topLeftCorner(Index, Index).
template<int CRows, int CCols>
FixedBlockXpr< CRows, CCols >::Type topLeftCorner ()
template<int CRows, int CCols>
const ConstFixedBlockXpr
< CRows, CCols >::Type 
topLeftCorner () const
 This is the const version of topLeftCorner<int, int>().
template<int CRows, int CCols>
FixedBlockXpr< CRows, CCols >::Type topLeftCorner (Index cRows, Index cCols)
template<int CRows, int CCols>
const ConstFixedBlockXpr
< CRows, CCols >::Type 
topLeftCorner (Index cRows, Index cCols) const
 This is the const version of topLeftCorner<int, int>(Index, Index).
BlockXpr topRightCorner (Index cRows, Index cCols)
const ConstBlockXpr topRightCorner (Index cRows, Index cCols) const
 This is the const version of topRightCorner(Index, Index).
template<int CRows, int CCols>
FixedBlockXpr< CRows, CCols >::Type topRightCorner ()
template<int CRows, int CCols>
const ConstFixedBlockXpr
< CRows, CCols >::Type 
topRightCorner () const
 This is the const version of topRightCorner<int, int>().
template<int CRows, int CCols>
FixedBlockXpr< CRows, CCols >::Type topRightCorner (Index cRows, Index cCols)
template<int CRows, int CCols>
const ConstFixedBlockXpr
< CRows, CCols >::Type 
topRightCorner (Index cRows, Index cCols) const
 This is the const version of topRightCorner<int, int>(Index, Index).
RowsBlockXpr topRows (Index n)
ConstRowsBlockXpr topRows (Index n) const
 This is the const version of topRows(Index).
template<int N>
NRowsBlockXpr< N >::Type topRows (Index n=N)
template<int N>
ConstNRowsBlockXpr< N >::Type topRows (Index n=N) const
 This is the const version of topRows<int>().
SparseSymmetricPermutationProduct
< Derived, Upper|Lower > 
twistedBy (const PermutationMatrix< Dynamic, Dynamic, StorageIndex > &perm) const
template<typename CustomUnaryOp >
const CwiseUnaryOp
< CustomUnaryOp, const Derived > 
unaryExpr (const CustomUnaryOp &func=CustomUnaryOp()) const
 Apply a unary operator coefficient-wise.
template<typename CustomViewOp >
const CwiseUnaryView
< CustomViewOp, const Derived > 
unaryViewExpr (const CustomViewOp &func=CustomViewOp()) const

Friends

template<typename T >
const CwiseBinaryOp
< internal::scalar_product_op
< T, Scalar >, Constant< T >
, Derived > 
operator* (const T &scalar, const StorageBaseType &expr)

Member Typedef Documentation

template<typename Derived>
typedef internal::traits<Derived>::StorageIndex Eigen::SparseMatrixBase< Derived >::StorageIndex

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

Reimplemented in Eigen::SparseMapBase< Derived, WriteAccessors >, and Eigen::SparseMapBase< Derived, ReadOnlyAccessors >.

template<typename Derived>
typedef Scalar Eigen::SparseMatrixBase< Derived >::value_type

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

It is an alias for the Scalar type


Member Enumeration Documentation

template<typename Derived>
anonymous enum
Enumerator:
RowsAtCompileTime 

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

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

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

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

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

See also:
RowsAtCompileTime, ColsAtCompileTime
IsVectorAtCompileTime 

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

Flags 

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


Member Function Documentation

template<typename Derived>
template<typename CustomBinaryOp , typename OtherDerived >
const CwiseBinaryOp<CustomBinaryOp, const Derived, const OtherDerived> Eigen::SparseMatrixBase< Derived >::binaryExpr ( const Eigen::SparseMatrixBase< OtherDerived > &  other,
const CustomBinaryOp &  func = CustomBinaryOp() 
) const [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()
template<typename Derived>
BlockXpr Eigen::SparseMatrixBase< 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.
Warning:
This method returns a read-only expression for any sparse matrices.
See also:
Sparse block operations
class Block, block(Index,Index)
template<typename Derived>
template<int NRows, int NCols>
FixedBlockXpr<NRows,NCols>::Type Eigen::SparseMatrixBase< Derived >::block ( Index  startRow,
Index  startCol 
) [inline]
Returns:
a fixed-size expression of a block in *this.

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

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

Example:

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); 
Warning:
This method returns a read-only expression for any sparse matrices.
See also:
Sparse block operations
class Block, block(Index,Index,Index,Index)
template<typename Derived>
template<int NRows, int NCols>
FixedBlockXpr<NRows,NCols>::Type Eigen::SparseMatrixBase< Derived >::block ( Index  startRow,
Index  startCol,
Index  blockRows,
Index  blockCols 
) [inline]
Returns:
an expression of a block in *this.
Template Parameters:
NRowsnumber of rows in block as specified at compile-time
NColsnumber of columns in block as specified at compile-time
Parameters:
startRowthe first row in the block
startColthe first column in the block
blockRowsnumber of rows in block as specified at run-time
blockColsnumber of columns in block as specified at run-time

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

Example:

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;
Warning:
This method returns a read-only expression for any sparse matrices.
See also:
Sparse block operations
class Block, block(Index,Index,Index,Index)
template<typename Derived>
BlockXpr Eigen::SparseMatrixBase< 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
Warning:
This method returns a read-only expression for any sparse matrices.
See also:
Sparse block operations
class Block, block(Index,Index,Index,Index)
template<typename Derived>
template<int CRows, int CCols>
FixedBlockXpr<CRows,CCols>::Type Eigen::SparseMatrixBase< Derived >::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
Warning:
This method returns a read-only expression for any sparse matrices.
See also:
Sparse block operations
class Block, block(Index,Index,Index,Index)
template<typename Derived>
template<int CRows, int CCols>
FixedBlockXpr<CRows,CCols>::Type Eigen::SparseMatrixBase< Derived >::bottomLeftCorner ( Index  cRows,
Index  cCols 
) [inline]
Returns:
an expression of a bottom-left corner of *this.
Template Parameters:
CRowsnumber of rows in corner as specified at compile-time
CColsnumber of columns in corner as specified at compile-time
Parameters:
cRowsnumber of rows in corner as specified at run-time
cColsnumber of columns in corner as specified at run-time

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

Example:

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
Warning:
This method returns a read-only expression for any sparse matrices.
See also:
Sparse block operations
class Block
template<typename Derived>
BlockXpr Eigen::SparseMatrixBase< 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
Warning:
This method returns a read-only expression for any sparse matrices.
See also:
Sparse block operations
class Block, block(Index,Index,Index,Index)
template<typename Derived>
template<int CRows, int CCols>
FixedBlockXpr<CRows,CCols>::Type Eigen::SparseMatrixBase< Derived >::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
Warning:
This method returns a read-only expression for any sparse matrices.
See also:
Sparse block operations
class Block, block(Index,Index,Index,Index)
template<typename Derived>
template<int CRows, int CCols>
FixedBlockXpr<CRows,CCols>::Type Eigen::SparseMatrixBase< Derived >::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
Warning:
This method returns a read-only expression for any sparse matrices.
See also:
Sparse block operations
class Block
template<typename Derived>
RowsBlockXpr Eigen::SparseMatrixBase< Derived >::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
Warning:
This method returns a read-write expression for row-major sparse matrices only. Otherwise, the returned expression is read-only.
See also:
Sparse block operations
class Block, block(Index,Index,Index,Index)
template<typename Derived>
template<int N>
NRowsBlockXpr<N>::Type Eigen::SparseMatrixBase< Derived >::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
Warning:
This method returns a read-write expression for row-major sparse matrices only. Otherwise, the returned expression is read-only.
See also:
Sparse block operations
class Block, block(Index,Index,Index,Index)
template<typename Derived>
template<typename NewType >
CastXpr<NewType>::Type Eigen::SparseMatrixBase< Derived >::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.

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

See also:
SparseCompressedBase::coeffs()
class CwiseUnaryOp
template<typename Derived>
ColXpr Eigen::SparseMatrixBase< Derived >::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
Warning:
This method returns a read-write expression for column-major sparse matrices only. Otherwise, the returned expression is read-only.
See also:
Sparse block operations
row(), class Block
template<typename Derived>
ConjugateReturnType Eigen::SparseMatrixBase< Derived >::conjugate ( ) const [inline]
Returns:
an expression of the complex conjugate of *this.

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

See also:
SparseCompressedBase::coeffs()
Math functions, MatrixBase::adjoint()
template<typename Derived>
const CwiseAbsReturnType Eigen::SparseMatrixBase< 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

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

See also:
SparseCompressedBase::coeffs()
cwiseAbs2()
template<typename Derived>
const CwiseAbs2ReturnType Eigen::SparseMatrixBase< 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

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

See also:
SparseCompressedBase::coeffs()
cwiseAbs()
template<typename Derived>
template<typename OtherDerived >
const CwiseBinaryOp<std::equal_to<Scalar>, const Derived, const OtherDerived> Eigen::SparseMatrixBase< Derived >::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()
template<typename Derived>
const CwiseScalarEqualReturnType Eigen::SparseMatrixBase< Derived >::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
template<typename Derived>
const CwiseInverseReturnType Eigen::SparseMatrixBase< 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

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

See also:
SparseCompressedBase::coeffs()
cwiseProduct()
template<typename Derived>
template<typename OtherDerived >
const CwiseBinaryOp<internal::scalar_max_op<Scalar,Scalar>, const Derived, const OtherDerived> Eigen::SparseMatrixBase< Derived >::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()
template<typename Derived>
const CwiseBinaryOp<internal::scalar_max_op<Scalar,Scalar>, const Derived, const ConstantReturnType> Eigen::SparseMatrixBase< Derived >::cwiseMax ( const Scalar &  other) const [inline]
Returns:
an expression of the coefficient-wise max of *this and scalar other
See also:
class CwiseBinaryOp, min()
template<typename Derived>
template<typename OtherDerived >
const CwiseBinaryOp<internal::scalar_min_op<Scalar,Scalar>, const Derived, const OtherDerived> Eigen::SparseMatrixBase< Derived >::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()
template<typename Derived>
const CwiseBinaryOp<internal::scalar_min_op<Scalar,Scalar>, const Derived, const ConstantReturnType> Eigen::SparseMatrixBase< Derived >::cwiseMin ( const Scalar &  other) const [inline]
Returns:
an expression of the coefficient-wise min of *this and scalar other
See also:
class CwiseBinaryOp, min()
template<typename Derived>
template<typename OtherDerived >
const CwiseBinaryOp<std::not_equal_to<Scalar>, const Derived, const OtherDerived> Eigen::SparseMatrixBase< Derived >::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()
template<typename Derived>
template<typename OtherDerived >
const CwiseBinaryOp< internal::scalar_product_op < Derived ::Scalar, OtherDerived ::Scalar>, const Derived , const OtherDerived > Eigen::SparseMatrixBase< Derived >::cwiseProduct ( const Eigen::SparseMatrixBase< OtherDerived > &  other) const [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
template<typename Derived>
template<typename OtherDerived >
const CwiseBinaryOp<internal::scalar_quotient_op<Scalar>, const Derived, const OtherDerived> Eigen::SparseMatrixBase< Derived >::cwiseQuotient ( const Eigen::SparseMatrixBase< OtherDerived > &  other) const [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()
template<typename Derived>
const CwiseSignReturnType Eigen::SparseMatrixBase< Derived >::cwiseSign ( ) const [inline]
Returns:
an expression of the coefficient-wise signum of *this.

Example:

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

Output:

 1 -1  1
-1  1  0

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

See also:
SparseCompressedBase::coeffs()
template<typename Derived>
const CwiseSqrtReturnType Eigen::SparseMatrixBase< 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

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

See also:
SparseCompressedBase::coeffs()
cwisePow(), cwiseSquare()
template<typename Derived>
const internal::eval<Derived>::type Eigen::SparseMatrixBase< Derived >::eval ( ) const [inline]
Returns:
the matrix or vector obtained by evaluating this expression.

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

template<typename Derived>
SegmentReturnType Eigen::SparseMatrixBase< Derived >::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)
template<typename Derived>
template<int N>
FixedSegmentReturnType<N>::Type Eigen::SparseMatrixBase< Derived >::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
template<typename Derived>
const ImagReturnType Eigen::SparseMatrixBase< Derived >::imag ( ) const [inline]
Returns:
an read-only expression of the imaginary part of *this.

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

See also:
SparseCompressedBase::coeffs()
real()
template<typename Derived>
NonConstImagReturnType Eigen::SparseMatrixBase< Derived >::imag ( ) [inline]
Returns:
a non const expression of the imaginary part of *this.

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

See also:
SparseCompressedBase::coeffs()
real()
template<typename Derived >
SparseMatrixBase< Derived >::InnerVectorReturnType Eigen::SparseMatrixBase< Derived >::innerVector ( Index  outer)
Returns:
the outer -th column (resp. row) of the matrix *this if *this is col-major (resp. row-major).
template<typename Derived >
const SparseMatrixBase< Derived >::ConstInnerVectorReturnType Eigen::SparseMatrixBase< Derived >::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.
template<typename Derived >
SparseMatrixBase< Derived >::InnerVectorsReturnType Eigen::SparseMatrixBase< Derived >::innerVectors ( Index  outerStart,
Index  outerSize 
)
Returns:
the outer -th column (resp. row) of the matrix *this if *this is col-major (resp. row-major).
template<typename Derived >
const SparseMatrixBase< Derived >::ConstInnerVectorsReturnType Eigen::SparseMatrixBase< Derived >::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.
template<typename Derived>
bool Eigen::SparseMatrixBase< Derived >::isVector ( ) const [inline]
Returns:
true if either the number of rows or the number of columns is equal to 1. In other words, this function returns
 rows()==1 || cols()==1 
See also:
rows(), cols(), IsVectorAtCompileTime.
template<typename Derived>
ColsBlockXpr Eigen::SparseMatrixBase< Derived >::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
Warning:
This method returns a read-write expression for column-major sparse matrices only. Otherwise, the returned expression is read-only.
See also:
Sparse block operations
class Block, block(Index,Index,Index,Index)
template<typename Derived>
template<int N>
NColsBlockXpr<N>::Type Eigen::SparseMatrixBase< Derived >::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
Warning:
This method returns a read-write expression for column-major sparse matrices only. Otherwise, the returned expression is read-only.
See also:
Sparse block operations
class Block, block(Index,Index,Index,Index)
template<typename Derived>
ColsBlockXpr Eigen::SparseMatrixBase< Derived >::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
Warning:
This method returns a read-write expression for column-major sparse matrices only. Otherwise, the returned expression is read-only.
See also:
Sparse block operations
class Block, block(Index,Index,Index,Index)
template<typename Derived>
template<int N>
NColsBlockXpr<N>::Type Eigen::SparseMatrixBase< Derived >::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
Warning:
This method returns a read-write expression for column-major sparse matrices only. Otherwise, the returned expression is read-only.
See also:
Sparse block operations
class Block, block(Index,Index,Index,Index)
template<typename Derived>
RowsBlockXpr Eigen::SparseMatrixBase< Derived >::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
Warning:
This method returns a read-write expression for row-major sparse matrices only. Otherwise, the returned expression is read-only.
See also:
Sparse block operations
class Block, block(Index,Index,Index,Index)
template<typename Derived>
template<int N>
NRowsBlockXpr<N>::Type Eigen::SparseMatrixBase< Derived >::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
Warning:
This method returns a read-write expression for row-major sparse matrices only. Otherwise, the returned expression is read-only.
See also:
Sparse block operations
class Block, block(Index,Index,Index,Index)
template<typename Derived>
template<typename OtherDerived >
const CwiseBinaryOp<internal::scalar_boolean_and_op, const Derived, const OtherDerived> Eigen::SparseMatrixBase< Derived >::operator&& ( const Eigen::SparseMatrixBase< OtherDerived > &  other) const [inline]
Returns:
an expression of the coefficient-wise boolean and operator of *this and other
Warning:
this operator is for expression of bool only.

Example:

Array3d v(-1,2,1), w(-3,2,3);
cout << ((v<w) && (v<0)) << endl;

Output:

0
0
0
See also:
operator||(), select()
template<typename Derived>
template<typename T >
const CwiseBinaryOp<internal::scalar_product_op<Scalar,T>,Derived,Constant<T> > Eigen::SparseMatrixBase< Derived >::operator* ( const T &  scalar) const
Returns:
an expression of *this scaled by the scalar factor scalar
Template Parameters:
Tis the scalar type of scalar. It must be compatible with the scalar type of the given expression.
template<typename Derived >
template<typename OtherDerived >
const Product< Derived, OtherDerived, AliasFreeProduct > Eigen::SparseMatrixBase< Derived >::operator* ( const SparseMatrixBase< OtherDerived > &  other) const [inline]
Returns:
an expression of the product of two sparse matrices. By default a conservative product preserving the symbolic non zeros is performed. The automatic pruning of the small values can be achieved by calling the pruned() function in which case a totally different product algorithm is employed:
 C = (A*B).pruned();             // supress numerical zeros (exact)
 C = (A*B).pruned(ref);
 C = (A*B).pruned(ref,epsilon);
where ref is a meaningful non zero reference value.
template<typename Derived>
template<typename OtherDerived >
const CwiseBinaryOp< sum <Scalar>, const Derived, const OtherDerived> Eigen::SparseMatrixBase< Derived >::operator+ ( const Eigen::SparseMatrixBase< OtherDerived > &  other) const
Returns:
an expression of the sum of *this and other
Note:
If you want to add a given scalar to all coefficients, see Cwise::operator+().
See also:
class CwiseBinaryOp, operator+=()
template<typename Derived>
template<typename OtherDerived >
const CwiseBinaryOp< difference <Scalar>, const Derived, const OtherDerived> Eigen::SparseMatrixBase< Derived >::operator- ( const Eigen::SparseMatrixBase< OtherDerived > &  other) const
Returns:
an expression of the difference of *this and other
Note:
If you want to substract a given scalar from all coefficients, see Cwise::operator-().
See also:
class CwiseBinaryOp, operator-=()
template<typename Derived>
const NegativeReturnType Eigen::SparseMatrixBase< Derived >::operator- ( ) const [inline]
Returns:
an expression of the opposite of *this

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

See also:
SparseCompressedBase::coeffs()
template<typename Derived>
template<typename T >
const CwiseBinaryOp<internal::scalar_quotient_op<Scalar,T>,Derived,Constant<T> > Eigen::SparseMatrixBase< Derived >::operator/ ( const T &  scalar) const
Returns:
an expression of *this divided by the scalar value scalar
Template Parameters:
Tis the scalar type of scalar. It must be compatible with the scalar type of the given expression.
template<typename Derived>
template<typename OtherDerived >
const CwiseBinaryOp<internal::scalar_boolean_or_op, const Derived, const OtherDerived> Eigen::SparseMatrixBase< Derived >::operator|| ( const Eigen::SparseMatrixBase< OtherDerived > &  other) const [inline]
Returns:
an expression of the coefficient-wise boolean or operator of *this and other
Warning:
this operator is for expression of bool only.

Example:

Array3d v(-1,2,1), w(-3,2,3);
cout << ((v<w) || (v<0)) << endl;

Output:

1
0
1
See also:
operator&&(), select()
template<typename Derived >
const SparseView< Derived > Eigen::SparseMatrixBase< Derived >::pruned ( const Scalar &  reference = Scalar(0),
const RealScalar &  epsilon = NumTraits<Scalar>::dummy_precision() 
) const [inline]
Returns:
an expression of *this with values smaller than reference * epsilon removed.

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

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

where ref is a meaningful non zero reference value.

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

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

See also:
SparseCompressedBase::coeffs()
imag()
template<typename Derived>
NonConstRealReturnType Eigen::SparseMatrixBase< Derived >::real ( ) [inline]
Returns:
a non const expression of the real part of *this.

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

See also:
SparseCompressedBase::coeffs()
imag()
template<typename Derived>
ColsBlockXpr Eigen::SparseMatrixBase< Derived >::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
Warning:
This method returns a read-write expression for column-major sparse matrices only. Otherwise, the returned expression is read-only.
See also:
Sparse block operations
class Block, block(Index,Index,Index,Index)
template<typename Derived>
template<int N>
NColsBlockXpr<N>::Type Eigen::SparseMatrixBase< Derived >::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
Warning:
This method returns a read-write expression for column-major sparse matrices only. Otherwise, the returned expression is read-only.
See also:
Sparse block operations
class Block, block(Index,Index,Index,Index)
template<typename Derived>
RowXpr Eigen::SparseMatrixBase< Derived >::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
Warning:
This method returns a read-write expression for row-major sparse matrices only. Otherwise, the returned expression is read-only.
See also:
Sparse block operations
col(), class Block
template<typename Derived>
SegmentReturnType Eigen::SparseMatrixBase< Derived >::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)
template<typename Derived>
template<int N>
FixedSegmentReturnType<N>::Type Eigen::SparseMatrixBase< Derived >::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
template<typename Derived>
Index Eigen::SparseMatrixBase< Derived >::size ( ) const [inline]
Returns:
the number of coefficients, which is rows()*cols().
See also:
rows(), cols().

Reimplemented from Eigen::EigenBase< Derived >.

template<typename Derived>
SegmentReturnType Eigen::SparseMatrixBase< Derived >::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)
template<typename Derived>
template<int N>
FixedSegmentReturnType<N>::Type Eigen::SparseMatrixBase< Derived >::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
template<typename Derived>
BlockXpr Eigen::SparseMatrixBase< 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
Warning:
This method returns a read-only expression for any sparse matrices.
See also:
Sparse block operations
class Block, block(Index,Index,Index,Index)
template<typename Derived>
template<int CRows, int CCols>
FixedBlockXpr<CRows,CCols>::Type Eigen::SparseMatrixBase< Derived >::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
Warning:
This method returns a read-only expression for any sparse matrices.
See also:
Sparse block operations
class Block, block(Index,Index,Index,Index)
template<typename Derived>
template<int CRows, int CCols>
FixedBlockXpr<CRows,CCols>::Type Eigen::SparseMatrixBase< Derived >::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
Warning:
This method returns a read-only expression for any sparse matrices.
See also:
Sparse block operations
class Block
template<typename Derived>
BlockXpr Eigen::SparseMatrixBase< 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
Warning:
This method returns a read-only expression for any sparse matrices.
See also:
Sparse block operations
class Block, block(Index,Index,Index,Index)
template<typename Derived>
template<int CRows, int CCols>
FixedBlockXpr<CRows,CCols>::Type Eigen::SparseMatrixBase< Derived >::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
Warning:
This method returns a read-only expression for any sparse matrices.
See also:
Sparse block operations
class Block, block<int,int>(Index,Index)
template<typename Derived>
template<int CRows, int CCols>
FixedBlockXpr<CRows,CCols>::Type Eigen::SparseMatrixBase< Derived >::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
Warning:
This method returns a read-only expression for any sparse matrices.
See also:
Sparse block operations
class Block
template<typename Derived>
RowsBlockXpr Eigen::SparseMatrixBase< Derived >::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
Warning:
This method returns a read-write expression for row-major sparse matrices only. Otherwise, the returned expression is read-only.
See also:
Sparse block operations
class Block, block(Index,Index,Index,Index)
template<typename Derived>
template<int N>
NRowsBlockXpr<N>::Type Eigen::SparseMatrixBase< Derived >::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
Warning:
This method returns a read-write expression for row-major sparse matrices only. Otherwise, the returned expression is read-only.
See also:
Sparse block operations
class Block, block(Index,Index,Index,Index)
template<typename Derived>
SparseSymmetricPermutationProduct<Derived,Upper|Lower> Eigen::SparseMatrixBase< Derived >::twistedBy ( const PermutationMatrix< Dynamic, Dynamic, StorageIndex > &  perm) const [inline]
Returns:
an expression of P H P^-1 where H is the matrix represented by *this
template<typename Derived>
template<typename CustomUnaryOp >
const CwiseUnaryOp<CustomUnaryOp, const Derived> Eigen::SparseMatrixBase< 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

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

See also:
SparseCompressedBase::coeffs()
unaryViewExpr, binaryExpr, class CwiseUnaryOp
template<typename Derived>
template<typename CustomViewOp >
const CwiseUnaryView<CustomViewOp, const Derived> Eigen::SparseMatrixBase< 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

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

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

Friends And Related Function Documentation

template<typename Derived>
template<typename T >
const CwiseBinaryOp<internal::scalar_product_op<T,Scalar>,Constant<T>,Derived> operator* ( const T &  scalar,
const StorageBaseType expr 
) [friend]
Returns:
an expression of expr scaled by the scalar factor scalar
Template Parameters:
Tis the scalar type of scalar. It must be compatible with the scalar type of the given expression.

The documentation for this class was generated from the following files:
 All Classes Functions Variables Typedefs Enumerations Enumerator Friends