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DenseBase< Derived > Class Template Reference

Detailed Description

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

Base class for all dense matrices, vectors, and arrays.

This class is the base that is inherited by all dense objects (matrix, vector, arrays, and related expression types). The common Eigen API for dense objects is contained in this class.

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

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

See Also
The class hierarchy
+ Inheritance diagram for DenseBase< Derived >:

Public Types

enum  {
  RowsAtCompileTime,
  ColsAtCompileTime,
  SizeAtCompileTime,
  MaxRowsAtCompileTime,
  MaxColsAtCompileTime,
  MaxSizeAtCompileTime,
  IsVectorAtCompileTime,
  Flags,
  IsRowMajor ,
  CoeffReadCost
}
 
typedef internal::traits
< Derived >::Index 
Index
 The type of indices. More...
 

Public Member Functions

bool all () const
 
bool allFinite () const
 
bool any () 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
 
ColXpr col (Index i)
 
ConstColXpr col (Index i) const
 
ConstColwiseReturnType colwise () const
 
ColwiseReturnType colwise ()
 
Index count () const
 
EvalReturnType eval () const
 
void fill (const Scalar &value)
 
template<unsigned int Added, unsigned int Removed>
const Flagged< Derived, Added,
Removed > 
flagged () const
 
const WithFormat< Derived > format (const IOFormat &fmt) const
 
bool hasNaN () 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
 
Index innerSize () const
 
template<typename OtherDerived >
bool isApprox (const DenseBase< OtherDerived > &other, const RealScalar &prec=NumTraits< Scalar >::dummy_precision()) const
 
bool isApproxToConstant (const Scalar &value, const RealScalar &prec=NumTraits< Scalar >::dummy_precision()) const
 
bool isConstant (const Scalar &value, const RealScalar &prec=NumTraits< Scalar >::dummy_precision()) const
 
template<typename Derived >
bool isMuchSmallerThan (const typename NumTraits< Scalar >::Real &other, const RealScalar &prec) const
 
template<typename OtherDerived >
bool isMuchSmallerThan (const DenseBase< OtherDerived > &other, const RealScalar &prec=NumTraits< Scalar >::dummy_precision()) const
 
bool isOnes (const RealScalar &prec=NumTraits< Scalar >::dummy_precision()) const
 
bool isZero (const RealScalar &prec=NumTraits< Scalar >::dummy_precision()) 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
 
internal::traits< Derived >::Scalar maxCoeff () const
 
template<typename IndexType >
internal::traits< Derived >::Scalar maxCoeff (IndexType *row, IndexType *col) const
 
template<typename IndexType >
internal::traits< Derived >::Scalar maxCoeff (IndexType *index) const
 
Scalar mean () 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
 
internal::traits< Derived >::Scalar minCoeff () const
 
template<typename IndexType >
internal::traits< Derived >::Scalar minCoeff (IndexType *row, IndexType *col) const
 
template<typename IndexType >
internal::traits< Derived >::Scalar minCoeff (IndexType *index) const
 
const NestByValue< Derived > nestByValue () const
 
Index nonZeros () const
 
CommaInitializer< Derived > operator<< (const Scalar &s)
 
template<typename OtherDerived >
CommaInitializer< Derived > operator<< (const DenseBase< OtherDerived > &other)
 
template<typename OtherDerived >
Derived & operator= (const DenseBase< OtherDerived > &other)
 
Derived & operator= (const DenseBase &other)
 
template<typename OtherDerived >
Derived & operator= (const EigenBase< OtherDerived > &other)
 Copies the generic expression other into *this. More...
 
Index outerSize () const
 
Scalar prod () const
 
template<typename Func >
internal::result_of< Func(typename
internal::traits< Derived >
::Scalar)>::type 
redux (const Func &func) const
 
template<int RowFactor, int ColFactor>
const Replicate< Derived,
RowFactor, ColFactor > 
replicate () const
 
const Replicate< Derived,
Dynamic, Dynamic
replicate (Index rowFacor, Index colFactor) const
 
void resize (Index newSize)
 
void resize (Index nbRows, Index nbCols)
 
ReverseReturnType reverse ()
 
ConstReverseReturnType reverse () const
 
void reverseInPlace ()
 
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
 
ConstRowwiseReturnType rowwise () const
 
RowwiseReturnType rowwise ()
 
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
 
template<typename ThenDerived , typename ElseDerived >
const Select< Derived,
ThenDerived, ElseDerived > 
select (const DenseBase< ThenDerived > &thenMatrix, const DenseBase< ElseDerived > &elseMatrix) const
 
template<typename ThenDerived >
const Select< Derived,
ThenDerived, typename
ThenDerived::ConstantReturnType > 
select (const DenseBase< ThenDerived > &thenMatrix, const typename ThenDerived::Scalar &elseScalar) const
 
template<typename ElseDerived >
const Select< Derived,
typename
ElseDerived::ConstantReturnType,
ElseDerived > 
select (const typename ElseDerived::Scalar &thenScalar, const DenseBase< ElseDerived > &elseMatrix) const
 
Derived & setConstant (const Scalar &value)
 
Derived & setLinSpaced (Index size, const Scalar &low, const Scalar &high)
 Sets a linearly space vector. More...
 
Derived & setLinSpaced (const Scalar &low, const Scalar &high)
 Sets a linearly space vector. More...
 
Derived & setOnes ()
 
Derived & setRandom ()
 
Derived & setZero ()
 
Scalar sum () const
 
template<typename OtherDerived >
void swap (const DenseBase< OtherDerived > &other, int=OtherDerived::ThisConstantIsPrivateInPlainObjectBase)
 
template<typename OtherDerived >
void swap (PlainObjectBase< OtherDerived > &other)
 
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
 
Eigen::Transpose< Derived > transpose ()
 
ConstTransposeReturnType transpose () const
 
void transposeInPlace ()
 
CoeffReturnType value () const
 
template<typename Visitor >
void visit (Visitor &func) const
 

Static Public Member Functions

static const ConstantReturnType Constant (Index rows, Index cols, const Scalar &value)
 
static const ConstantReturnType Constant (Index size, const Scalar &value)
 
static const ConstantReturnType Constant (const Scalar &value)
 
static const
SequentialLinSpacedReturnType 
LinSpaced (Sequential_t, Index size, const Scalar &low, const Scalar &high)
 Sets a linearly space vector. More...
 
static const
RandomAccessLinSpacedReturnType 
LinSpaced (Index size, const Scalar &low, const Scalar &high)
 Sets a linearly space vector. More...
 
static const
SequentialLinSpacedReturnType 
LinSpaced (Sequential_t, const Scalar &low, const Scalar &high)
 Sets a linearly space vector. More...
 
static const
RandomAccessLinSpacedReturnType 
LinSpaced (const Scalar &low, const Scalar &high)
 Sets a linearly space vector. More...
 
template<typename CustomNullaryOp >
static const CwiseNullaryOp
< CustomNullaryOp, Derived > 
NullaryExpr (Index rows, Index cols, const CustomNullaryOp &func)
 
template<typename CustomNullaryOp >
static const CwiseNullaryOp
< CustomNullaryOp, Derived > 
NullaryExpr (Index size, const CustomNullaryOp &func)
 
template<typename CustomNullaryOp >
static const CwiseNullaryOp
< CustomNullaryOp, Derived > 
NullaryExpr (const CustomNullaryOp &func)
 
static const ConstantReturnType Ones (Index rows, Index cols)
 
static const ConstantReturnType Ones (Index size)
 
static const ConstantReturnType Ones ()
 
static const CwiseNullaryOp
< internal::scalar_random_op
< Scalar >, Derived > 
Random (Index rows, Index cols)
 
static const CwiseNullaryOp
< internal::scalar_random_op
< Scalar >, Derived > 
Random (Index size)
 
static const CwiseNullaryOp
< internal::scalar_random_op
< Scalar >, Derived > 
Random ()
 
static const ConstantReturnType Zero (Index rows, Index cols)
 
static const ConstantReturnType Zero (Index size)
 
static const ConstantReturnType Zero ()
 

Protected Member Functions

 DenseBase ()
 

Related Functions

(Note that these are not member functions.)

template<typename Derived >
std::ostream & operator<< (std::ostream &s, const DenseBase< Derived > &m)
 

Member Typedef Documentation

typedef internal::traits<Derived>::Index Index

The type of indices.

To change this, #define the preprocessor symbol EIGEN_DEFAULT_DENSE_INDEX_TYPE.

See Also
Preprocessor directives.

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
MaxRowsAtCompileTime 

This value is equal to the maximum possible number of rows that this expression might have. If this expression might have an arbitrarily high number of rows, this value is set to Dynamic.

This value is useful to know when evaluating an expression, in order to determine whether it is possible to avoid doing a dynamic memory allocation.

See Also
RowsAtCompileTime, MaxColsAtCompileTime, MaxSizeAtCompileTime
MaxColsAtCompileTime 

This value is equal to the maximum possible number of columns that this expression might have. If this expression might have an arbitrarily high number of columns, this value is set to Dynamic.

This value is useful to know when evaluating an expression, in order to determine whether it is possible to avoid doing a dynamic memory allocation.

See Also
ColsAtCompileTime, MaxRowsAtCompileTime, MaxSizeAtCompileTime
MaxSizeAtCompileTime 

This value is equal to the maximum possible number of coefficients that this expression might have. If this expression might have an arbitrarily high number of coefficients, this value is set to Dynamic.

This value is useful to know when evaluating an expression, in order to determine whether it is possible to avoid doing a dynamic memory allocation.

See Also
SizeAtCompileTime, MaxRowsAtCompileTime, MaxColsAtCompileTime
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.

IsRowMajor 

True if this expression has row-major storage order.

CoeffReadCost 

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

Constructor & Destructor Documentation

DenseBase ( )
inlineprotected

Default constructor. Do nothing.

Member Function Documentation

bool all ( ) const
inline
Returns
true if all coefficients are true

Example:

Vector3f boxMin(Vector3f::Zero()), boxMax(Vector3f::Ones());
Vector3f p0 = Vector3f::Random(), p1 = Vector3f::Random().cwiseAbs();
// let's check if p0 and p1 are inside the axis aligned box defined by the corners boxMin,boxMax:
cout << "Is (" << p0.transpose() << ") inside the box: "
<< ((boxMin.array()<p0.array()).all() && (boxMax.array()>p0.array()).all()) << endl;
cout << "Is (" << p1.transpose() << ") inside the box: "
<< ((boxMin.array()<p1.array()).all() && (boxMax.array()>p1.array()).all()) << endl;

Output:

Is (  0.68 -0.211  0.566) inside the box: 0
Is (0.597 0.823 0.605) inside the box: 1
See Also
any(), Cwise::operator<()

References Eigen::Dynamic.

bool allFinite ( ) const
inline
Returns
true if *this contains only finite numbers, i.e., no NaN and no +/-INF values.
See Also
hasNaN()
bool any ( ) const
inline
Returns
true if at least one coefficient is true
See Also
all()

References Eigen::Dynamic.

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:

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:

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:

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:

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:

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:

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:

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:

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:

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>().

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

Example:

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 VectorwiseOp< ExpressionType, Direction >::cross().

ConstColXpr col ( Index  i) const
inline

This is the const version of col().

const DenseBase< Derived >::ConstColwiseReturnType colwise ( ) const
inline
Returns
a VectorwiseOp wrapper of *this providing additional partial reduction operations

Example:

cout << "Here is the matrix m:" << endl << m << endl;
cout << "Here is the sum of each column:" << endl << m.colwise().sum() << endl;
cout << "Here is the maximum absolute value of each column:"
<< endl << m.cwiseAbs().colwise().maxCoeff() << endl;

Output:

Here is the matrix m:
  0.68  0.597  -0.33
-0.211  0.823  0.536
 0.566 -0.605 -0.444
Here is the sum of each column:
  1.04  0.815 -0.238
Here is the maximum absolute value of each column:
 0.68 0.823 0.536
See Also
rowwise(), class VectorwiseOp, Reductions, visitors and broadcasting

Referenced by Eigen::umeyama().

DenseBase< Derived >::ColwiseReturnType colwise ( )
inline
Returns
a writable VectorwiseOp wrapper of *this providing additional partial reduction operations
See Also
rowwise(), class VectorwiseOp, Reductions, visitors and broadcasting
const DenseBase< Derived >::ConstantReturnType Constant ( Index  nbRows,
Index  nbCols,
const Scalar &  value 
)
inlinestatic
Returns
an expression of a constant matrix of value value

The parameters nbRows and nbCols are the number of rows and of columns of the returned matrix. Must be compatible with this DenseBase type.

This variant is meant to be used for dynamic-size matrix types. For fixed-size types, it is redundant to pass nbRows and nbCols as arguments, so Zero() should be used instead.

The template parameter CustomNullaryOp is the type of the functor.

See Also
class CwiseNullaryOp

References DenseBase< Derived >::NullaryExpr().

const DenseBase< Derived >::ConstantReturnType Constant ( Index  size,
const Scalar &  value 
)
inlinestatic
Returns
an expression of a constant matrix of value value

The parameter size is the size of the returned vector. Must be compatible with this DenseBase type.

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.

This variant is meant to be used for dynamic-size vector types. For fixed-size types, it is redundant to pass size as argument, so Zero() should be used instead.

The template parameter CustomNullaryOp is the type of the functor.

See Also
class CwiseNullaryOp

References DenseBase< Derived >::NullaryExpr().

const DenseBase< Derived >::ConstantReturnType Constant ( const Scalar &  value)
inlinestatic
Returns
an expression of a constant matrix of value value

This variant is only for fixed-size DenseBase types. For dynamic-size types, you need to use the variants taking size arguments.

The template parameter CustomNullaryOp is the type of the functor.

See Also
class CwiseNullaryOp

References DenseBase< Derived >::NullaryExpr().

DenseBase< Derived >::Index count ( ) const
inline
Returns
the number of coefficients which evaluate to true
See Also
all(), any()
EvalReturnType 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.

void fill ( const Scalar &  val)
inline

Alias for setConstant(): sets all coefficients in this expression to val.

See Also
setConstant(), Constant(), class CwiseNullaryOp
const Flagged< Derived, Added, Removed > flagged ( ) const
inline
Returns
an expression of *this with added and removed flags

This is mostly for internal use.

See Also
class Flagged
const WithFormat< Derived > format ( const IOFormat fmt) const
inline
Returns
a WithFormat proxy object allowing to print a matrix the with given format fmt.

See class IOFormat for some examples.

See Also
class IOFormat, class WithFormat
bool hasNaN ( ) const
inline
Returns
true is *this contains at least one Not A Number (NaN).
See Also
allFinite()
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:

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:

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>().

Index innerSize ( ) const
inline
Returns
the inner size.
Note
For a vector, this is just the size. For a matrix (non-vector), this is the minor dimension with respect to the storage order, i.e., the number of rows for a column-major matrix, and the number of columns for a row-major matrix.

References DenseBase< Derived >::IsRowMajor, and DenseBase< Derived >::IsVectorAtCompileTime.

bool isApprox ( const DenseBase< OtherDerived > &  other,
const RealScalar &  prec = NumTraits<Scalar>::dummy_precision() 
) const
Returns
true if *this is approximately equal to other, within the precision determined by prec.
Note
The fuzzy compares are done multiplicatively. Two vectors $ v $ and $ w $ are considered to be approximately equal within precision $ p $ if

\[ \Vert v - w \Vert \leqslant p\,\min(\Vert v\Vert, \Vert w\Vert). \]

For matrices, the comparison is done using the Hilbert-Schmidt norm (aka Frobenius norm L2 norm).
Because of the multiplicativeness of this comparison, one can't use this function to check whether *this is approximately equal to the zero matrix or vector. Indeed, isApprox(zero) returns false unless *this itself is exactly the zero matrix or vector. If you want to test whether *this is zero, use internal::isMuchSmallerThan(const RealScalar&, RealScalar) instead.
See Also
internal::isMuchSmallerThan(const RealScalar&, RealScalar) const

Referenced by Transform< Scalar, Dim, Mode, _Options >::isApprox().

bool isApproxToConstant ( const Scalar &  val,
const RealScalar &  prec = NumTraits<Scalar>::dummy_precision() 
) const
Returns
true if all coefficients in this matrix are approximately equal to val, to within precision prec
bool isConstant ( const Scalar &  val,
const RealScalar &  prec = NumTraits<Scalar>::dummy_precision() 
) const

This is just an alias for isApproxToConstant().

Returns
true if all coefficients in this matrix are approximately equal to value, to within precision prec
bool isMuchSmallerThan ( const typename NumTraits< Scalar >::Real &  other,
const RealScalar &  prec 
) const
Returns
true if the norm of *this is much smaller than other, within the precision determined by prec.
Note
The fuzzy compares are done multiplicatively. A vector $ v $ is considered to be much smaller than $ x $ within precision $ p $ if

\[ \Vert v \Vert \leqslant p\,\vert x\vert. \]

For matrices, the comparison is done using the Hilbert-Schmidt norm. For this reason, the value of the reference scalar other should come from the Hilbert-Schmidt norm of a reference matrix of same dimensions.

See Also
isApprox(), isMuchSmallerThan(const DenseBase<OtherDerived>&, RealScalar) const
bool isMuchSmallerThan ( const DenseBase< OtherDerived > &  other,
const RealScalar &  prec = NumTraits<Scalar>::dummy_precision() 
) const
Returns
true if the norm of *this is much smaller than the norm of other, within the precision determined by prec.
Note
The fuzzy compares are done multiplicatively. A vector $ v $ is considered to be much smaller than a vector $ w $ within precision $ p $ if

\[ \Vert v \Vert \leqslant p\,\Vert w\Vert. \]

For matrices, the comparison is done using the Hilbert-Schmidt norm.
See Also
isApprox(), isMuchSmallerThan(const RealScalar&, RealScalar) const
bool isOnes ( const RealScalar &  prec = NumTraits<Scalar>::dummy_precision()) const
Returns
true if *this is approximately equal to the matrix where all coefficients are equal to 1, within the precision given by prec.

Example:

m(0,2) += 1e-4;
cout << "Here's the matrix m:" << endl << m << endl;
cout << "m.isOnes() returns: " << m.isOnes() << endl;
cout << "m.isOnes(1e-3) returns: " << m.isOnes(1e-3) << endl;

Output:

Here's the matrix m:
1 1 1
1 1 1
1 1 1
m.isOnes() returns: 0
m.isOnes(1e-3) returns: 1
See Also
class CwiseNullaryOp, Ones()
bool isZero ( const RealScalar &  prec = NumTraits<Scalar>::dummy_precision()) const
Returns
true if *this is approximately equal to the zero matrix, within the precision given by prec.

Example:

m(0,2) = 1e-4;
cout << "Here's the matrix m:" << endl << m << endl;
cout << "m.isZero() returns: " << m.isZero() << endl;
cout << "m.isZero(1e-3) returns: " << m.isZero(1e-3) << endl;

Output:

Here's the matrix m:
     0      0 0.0001
     0      0      0
     0      0      0
m.isZero() returns: 0
m.isZero(1e-3) returns: 1
See Also
class CwiseNullaryOp, Zero()
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>().

const DenseBase< Derived >::SequentialLinSpacedReturnType LinSpaced ( Sequential_t  ,
Index  size,
const Scalar &  low,
const Scalar &  high 
)
inlinestatic

Sets a linearly space vector.

The function generates 'size' equally spaced values in the closed interval [low,high]. This particular version of LinSpaced() uses sequential access, i.e. vector access is assumed to be a(0), a(1), ..., a(size). This assumption allows for better vectorization and yields faster code than the random access version.

When size is set to 1, a vector of length 1 containing 'high' is returned.

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.

Example:

cout << VectorXi::LinSpaced(Sequential,4,7,10).transpose() << endl;
cout << VectorXd::LinSpaced(Sequential,5,0.0,1.0).transpose() << endl;

Output:

 7  8  9 10
   0 0.25  0.5 0.75    1
See Also
setLinSpaced(Index,const Scalar&,const Scalar&), LinSpaced(Index,Scalar,Scalar), CwiseNullaryOp

References DenseBase< Derived >::NullaryExpr().

const DenseBase< Derived >::RandomAccessLinSpacedReturnType LinSpaced ( Index  size,
const Scalar &  low,
const Scalar &  high 
)
inlinestatic

Sets a linearly space vector.

The function generates 'size' equally spaced values in the closed interval [low,high]. When size is set to 1, a vector of length 1 containing 'high' is returned.

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.

Example:

cout << VectorXi::LinSpaced(4,7,10).transpose() << endl;
cout << VectorXd::LinSpaced(5,0.0,1.0).transpose() << endl;

Output:

 7  8  9 10
   0 0.25  0.5 0.75    1
See Also
setLinSpaced(Index,const Scalar&,const Scalar&), LinSpaced(Sequential_t,Index,const Scalar&,const Scalar&,Index), CwiseNullaryOp

References DenseBase< Derived >::NullaryExpr().

const DenseBase< Derived >::SequentialLinSpacedReturnType LinSpaced ( Sequential_t  ,
const Scalar &  low,
const Scalar &  high 
)
inlinestatic

Sets a linearly space vector.

The function generates 'size' equally spaced values in the closed interval [low,high]. This particular version of LinSpaced() uses sequential access, i.e. vector access is assumed to be a(0), a(1), ..., a(size). This assumption allows for better vectorization and yields faster code than the random access version.

When size is set to 1, a vector of length 1 containing 'high' is returned.

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.

Example:

cout << VectorXi::LinSpaced(Sequential,4,7,10).transpose() << endl;
cout << VectorXd::LinSpaced(Sequential,5,0.0,1.0).transpose() << endl;

Output:

 7  8  9 10
   0 0.25  0.5 0.75    1
See Also
setLinSpaced(Index,const Scalar&,const Scalar&), LinSpaced(Index,Scalar,Scalar), CwiseNullaryOp Special version for fixed size types which does not require the size parameter.

References DenseBase< Derived >::NullaryExpr().

const DenseBase< Derived >::RandomAccessLinSpacedReturnType LinSpaced ( const Scalar &  low,
const Scalar &  high 
)
inlinestatic

Sets a linearly space vector.

The function generates 'size' equally spaced values in the closed interval [low,high]. When size is set to 1, a vector of length 1 containing 'high' is returned.

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.

Example:

cout << VectorXi::LinSpaced(4,7,10).transpose() << endl;
cout << VectorXd::LinSpaced(5,0.0,1.0).transpose() << endl;

Output:

 7  8  9 10
   0 0.25  0.5 0.75    1
See Also
setLinSpaced(Index,const Scalar&,const Scalar&), LinSpaced(Sequential_t,Index,const Scalar&,const Scalar&,Index), CwiseNullaryOp Special version for fixed size types which does not require the size parameter.

References DenseBase< Derived >::NullaryExpr().

internal::traits< Derived >::Scalar maxCoeff ( ) const
inline
Returns
the maximum of all coefficients of *this.
Warning
the result is undefined if *this contains NaN.
internal::traits< Derived >::Scalar maxCoeff ( IndexType *  rowPtr,
IndexType *  colPtr 
) const
Returns
the maximum of all coefficients of *this and puts in *row and *col its location.
Warning
the result is undefined if *this contains NaN.
See Also
DenseBase::minCoeff(IndexType*,IndexType*), DenseBase::visitor(), DenseBase::maxCoeff()
internal::traits< Derived >::Scalar maxCoeff ( IndexType *  index) const
Returns
the maximum of all coefficients of *this and puts in *index its location.
Warning
the result is undefined if *this contains NaN.
See Also
DenseBase::maxCoeff(IndexType*,IndexType*), DenseBase::minCoeff(IndexType*,IndexType*), DenseBase::visitor(), DenseBase::maxCoeff()
internal::traits< Derived >::Scalar mean ( ) const
inline
Returns
the mean of all coefficients of *this
See Also
trace(), prod(), sum()
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>().

internal::traits< Derived >::Scalar minCoeff ( ) const
inline
Returns
the minimum of all coefficients of *this.
Warning
the result is undefined if *this contains NaN.
internal::traits< Derived >::Scalar minCoeff ( IndexType *  rowId,
IndexType *  colId 
) const
Returns
the minimum of all coefficients of *this and puts in *row and *col its location.
Warning
the result is undefined if *this contains NaN.
See Also
DenseBase::minCoeff(Index*), DenseBase::maxCoeff(Index*,Index*), DenseBase::visitor(), DenseBase::minCoeff()
internal::traits< Derived >::Scalar minCoeff ( IndexType *  index) const
Returns
the minimum of all coefficients of *this and puts in *index its location.
Warning
the result is undefined if *this contains NaN.
See Also
DenseBase::minCoeff(IndexType*,IndexType*), DenseBase::maxCoeff(IndexType*,IndexType*), DenseBase::visitor(), DenseBase::minCoeff()
const NestByValue< Derived > nestByValue ( ) const
inline
Returns
an expression of the temporary version of *this.
Index nonZeros ( ) const
inline
Returns
the number of nonzero coefficients which is in practice the number of stored coefficients.
const CwiseNullaryOp< CustomNullaryOp, Derived > NullaryExpr ( Index  rows,
Index  cols,
const CustomNullaryOp &  func 
)
inlinestatic
Returns
an expression of a matrix defined by a custom functor func

The parameters rows and cols are the number of rows and of columns of the returned matrix. Must be compatible with this MatrixBase type.

This variant is meant to be used for dynamic-size matrix types. For fixed-size types, it is redundant to pass rows and cols as arguments, so Zero() should be used instead.

The template parameter CustomNullaryOp is the type of the functor.

See Also
class CwiseNullaryOp

Referenced by DenseBase< Derived >::Constant(), MatrixBase< Derived >::Identity(), and DenseBase< Derived >::LinSpaced().

const CwiseNullaryOp< CustomNullaryOp, Derived > NullaryExpr ( Index  size,
const CustomNullaryOp &  func 
)
inlinestatic
Returns
an expression of a matrix defined by a custom functor func

The parameter size is the size of the returned vector. Must be compatible with this MatrixBase type.

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.

This variant is meant to be used for dynamic-size vector types. For fixed-size types, it is redundant to pass size as argument, so Zero() should be used instead.

The template parameter CustomNullaryOp is the type of the functor.

Here is an example with C++11 random generators:

#include <Eigen/Core>
#include <iostream>
#include <random>
using namespace Eigen;
int main() {
std::default_random_engine generator;
std::poisson_distribution<int> distribution(4.1);
auto poisson = [&] (int) {return distribution(generator);};
std::cout << v << "\n";
}

Output:

2 3 1 4 3 4 4 3 2 3
See Also
class CwiseNullaryOp
const CwiseNullaryOp< CustomNullaryOp, Derived > NullaryExpr ( const CustomNullaryOp &  func)
inlinestatic
Returns
an expression of a matrix defined by a custom functor func

This variant is only for fixed-size DenseBase types. For dynamic-size types, you need to use the variants taking size arguments.

The template parameter CustomNullaryOp is the type of the functor.

See Also
class CwiseNullaryOp
const DenseBase< Derived >::ConstantReturnType Ones ( Index  nbRows,
Index  nbCols 
)
inlinestatic
Returns
an expression of a matrix where all coefficients equal one.

The parameters nbRows and nbCols are the number of rows and of columns of the returned matrix. Must be compatible with this MatrixBase type.

This variant is meant to be used for dynamic-size matrix types. For fixed-size types, it is redundant to pass rows and cols as arguments, so Ones() should be used instead.

Example:

cout << MatrixXi::Ones(2,3) << endl;

Output:

1 1 1
1 1 1
See Also
Ones(), Ones(Index), isOnes(), class Ones
const DenseBase< Derived >::ConstantReturnType Ones ( Index  newSize)
inlinestatic
Returns
an expression of a vector where all coefficients equal one.

The parameter newSize is the size of the returned vector. Must be compatible with this MatrixBase type.

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.

This variant is meant to be used for dynamic-size vector types. For fixed-size types, it is redundant to pass size as argument, so Ones() should be used instead.

Example:

cout << 6 * RowVectorXi::Ones(4) << endl;
cout << VectorXf::Ones(2) << endl;

Output:

6 6 6 6
1
1
See Also
Ones(), Ones(Index,Index), isOnes(), class Ones
const DenseBase< Derived >::ConstantReturnType Ones ( )
inlinestatic
Returns
an expression of a fixed-size matrix or vector where all coefficients equal one.

This variant is only for fixed-size MatrixBase types. For dynamic-size types, you need to use the variants taking size arguments.

Example:

cout << Matrix2d::Ones() << endl;
cout << 6 * RowVector4i::Ones() << endl;

Output:

1 1
1 1
6 6 6 6
See Also
Ones(Index), Ones(Index,Index), isOnes(), class Ones
CommaInitializer< Derived > operator<< ( const Scalar &  s)
inline

Convenient operator to set the coefficients of a matrix.

The coefficients must be provided in a row major order and exactly match the size of the matrix. Otherwise an assertion is raised.

Example:

m1 << 1, 2, 3,
4, 5, 6,
7, 8, 9;
cout << m1 << endl << endl;
m2.block(0,0, 2,2) << 10, 11, 12, 13;
cout << m2 << endl << endl;
v1 << 14, 15;
m2 << v1.transpose(), 16,
v1, m1.block(1,1,2,2);
cout << m2 << endl;

Output:

1 2 3
4 5 6
7 8 9

10 11  0
12 13  0
 0  0  1

14 15 16
14  5  6
15  8  9
Note
According the c++ standard, the argument expressions of this comma initializer are evaluated in arbitrary order.
See Also
CommaInitializer::finished(), class CommaInitializer
CommaInitializer< Derived > operator<< ( const DenseBase< OtherDerived > &  other)
inline
Derived & operator= ( const DenseBase< OtherDerived > &  other)
inline

Copies other into *this.

Returns
a reference to *this.
Derived & operator= ( const DenseBase< Derived > &  other)
inline

Special case of the template operator=, in order to prevent the compiler from generating a default operator= (issue hit with g++ 4.1)

Derived & operator= ( const EigenBase< OtherDerived > &  other)

Copies the generic expression other into *this.

The expression must provide a (templated) evalTo(Derived& dst) const function which does the actual job. In practice, this allows any user to write its own special matrix without having to modify MatrixBase

Returns
a reference to *this.

References EigenBase< Derived >::derived().

Index outerSize ( ) 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.
Returns
the outer size.
Note
For a vector, this returns just 1. For a matrix (non-vector), this is the major dimension with respect to the storage order, i.e., the number of columns for a column-major matrix, and the number of rows for a row-major matrix.

References DenseBase< Derived >::IsRowMajor, and DenseBase< Derived >::IsVectorAtCompileTime.

internal::traits< Derived >::Scalar prod ( ) const
inline
Returns
the product of all coefficients of *this

Example:

cout << "Here is the matrix m:" << endl << m << endl;
cout << "Here is the product of all the coefficients:" << endl << m.prod() << endl;

Output:

Here is the matrix m:
  0.68  0.597  -0.33
-0.211  0.823  0.536
 0.566 -0.605 -0.444
Here is the product of all the coefficients:
0.0019
See Also
sum(), mean(), trace()

References Eigen::Dynamic.

const CwiseNullaryOp< internal::scalar_random_op< typename internal::traits< Derived >::Scalar >, Derived > Random ( Index  rows,
Index  cols 
)
inlinestatic
Returns
a random matrix expression

Numbers are uniformly spread through their whole definition range for integer types, and in the [-1:1] range for floating point scalar types.

The parameters rows and cols are the number of rows and of columns of the returned matrix. Must be compatible with this MatrixBase type.

Warning
This function is not re-entrant.

This variant is meant to be used for dynamic-size matrix types. For fixed-size types, it is redundant to pass rows and cols as arguments, so Random() should be used instead.

Example:

cout << MatrixXi::Random(2,3) << endl;

Output:

 7  6  9
-2  6 -6

This expression has the "evaluate before nesting" flag so that it will be evaluated into a temporary matrix whenever it is nested in a larger expression. This prevents unexpected behavior with expressions involving random matrices.

See DenseBase::NullaryExpr(Index, const CustomNullaryOp&) for an example using C++11 random generators.

See Also
DenseBase::setRandom(), DenseBase::Random(Index), DenseBase::Random()
const CwiseNullaryOp< internal::scalar_random_op< typename internal::traits< Derived >::Scalar >, Derived > Random ( Index  size)
inlinestatic
Returns
a random vector expression

Numbers are uniformly spread through their whole definition range for integer types, and in the [-1:1] range for floating point scalar types.

The parameter size is the size of the returned vector. Must be compatible with this MatrixBase type.

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.

Warning
This function is not re-entrant.

This variant is meant to be used for dynamic-size vector types. For fixed-size types, it is redundant to pass size as argument, so Random() should be used instead.

Example:

cout << VectorXi::Random(2) << endl;

Output:

 7
-2

This expression has the "evaluate before nesting" flag so that it will be evaluated into a temporary vector whenever it is nested in a larger expression. This prevents unexpected behavior with expressions involving random matrices.

See Also
DenseBase::setRandom(), DenseBase::Random(Index,Index), DenseBase::Random()
const CwiseNullaryOp< internal::scalar_random_op< typename internal::traits< Derived >::Scalar >, Derived > Random ( )
inlinestatic
Returns
a fixed-size random matrix or vector expression

Numbers are uniformly spread through their whole definition range for integer types, and in the [-1:1] range for floating point scalar types.

This variant is only for fixed-size MatrixBase types. For dynamic-size types, you need to use the variants taking size arguments.

Example:

cout << 100 * Matrix2i::Random() << endl;

Output:

 700  600
-200  600

This expression has the "evaluate before nesting" flag so that it will be evaluated into a temporary matrix whenever it is nested in a larger expression. This prevents unexpected behavior with expressions involving random matrices.

Warning
This function is not re-entrant.
See Also
DenseBase::setRandom(), DenseBase::Random(Index,Index), DenseBase::Random(Index)
internal::result_of<Func(typename internal::traits<Derived>::Scalar)>::type redux ( const Func &  func) const
inline
Returns
the result of a full redux operation on the whole matrix or vector using func

The template parameter BinaryOp is the type of the functor func which must be an associative operator. Both current STL and TR1 functor styles are handled.

See Also
DenseBase::sum(), DenseBase::minCoeff(), DenseBase::maxCoeff(), MatrixBase::colwise(), MatrixBase::rowwise()
const Replicate< Derived, RowFactor, ColFactor > replicate ( ) const
inline
Returns
an expression of the replication of *this

Example:

cout << "Here is the matrix m:" << endl << m << endl;
cout << "m.replicate<3,2>() = ..." << endl;
cout << m.replicate<3,2>() << endl;

Output:

Here is the matrix m:
 7  6  9
-2  6 -6
m.replicate<3,2>() = ...
 7  6  9  7  6  9
-2  6 -6 -2  6 -6
 7  6  9  7  6  9
-2  6 -6 -2  6 -6
 7  6  9  7  6  9
-2  6 -6 -2  6 -6
See Also
VectorwiseOp::replicate(), DenseBase::replicate(Index,Index), class Replicate
const Replicate< Derived, Dynamic, Dynamic > replicate ( Index  rowFactor,
Index  colFactor 
) const
inline
Returns
an expression of the replication of *this

Example:

cout << "Here is the vector v:" << endl << v << endl;
cout << "v.replicate(2,5) = ..." << endl;
cout << v.replicate(2,5) << endl;

Output:

Here is the vector v:
 7
-2
 6
v.replicate(2,5) = ...
 7  7  7  7  7
-2 -2 -2 -2 -2
 6  6  6  6  6
 7  7  7  7  7
-2 -2 -2 -2 -2
 6  6  6  6  6
See Also
VectorwiseOp::replicate(), DenseBase::replicate<int,int>(), class Replicate
void resize ( Index  newSize)
inline

Only plain matrices/arrays, not expressions, may be resized; therefore the only useful resize methods are Matrix::resize() and Array::resize(). The present method only asserts that the new size equals the old size, and does nothing else.

void resize ( Index  nbRows,
Index  nbCols 
)
inline

Only plain matrices/arrays, not expressions, may be resized; therefore the only useful resize methods are Matrix::resize() and Array::resize(). The present method only asserts that the new size equals the old size, and does nothing else.

DenseBase< Derived >::ReverseReturnType reverse ( )
inline
Returns
an expression of the reverse of *this.

Example:

cout << "Here is the matrix m:" << endl << m << endl;
cout << "Here is the reverse of m:" << endl << m.reverse() << endl;
cout << "Here is the coefficient (1,0) in the reverse of m:" << endl
<< m.reverse()(1,0) << endl;
cout << "Let us overwrite this coefficient with the value 4." << endl;
m.reverse()(1,0) = 4;
cout << "Now the matrix m is:" << endl << m << endl;

Output:

Here is the matrix m:
 7  6 -3  1
-2  9  6  0
 6 -6 -5  3
Here is the reverse of m:
 3 -5 -6  6
 0  6  9 -2
 1 -3  6  7
Here is the coefficient (1,0) in the reverse of m:
0
Let us overwrite this coefficient with the value 4.
Now the matrix m is:
 7  6 -3  1
-2  9  6  4
 6 -6 -5  3
const DenseBase< Derived >::ConstReverseReturnType reverse ( ) const
inline

This is the const version of reverse().

void reverseInPlace ( )
inline

This is the "in place" version of reverse: it reverses *this.

In most cases it is probably better to simply use the reversed expression of a matrix. However, when reversing the matrix data itself is really needed, then this "in-place" version is probably the right choice because it provides the following additional features:

  • less error prone: doing the same operation with .reverse() requires special care:
    m = m.reverse().eval();
  • this API allows to avoid creating a temporary (the current implementation creates a temporary, but that could be avoided using swap)
  • it allows future optimizations (cache friendliness, etc.)
See Also
reverse()
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:

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 VectorwiseOp< ExpressionType, Direction >::cross(), and Transform< Scalar, Dim, Mode, _Options >::pretranslate().

ConstRowXpr row ( Index  i) const
inline

This is the const version of row().

const DenseBase< Derived >::ConstRowwiseReturnType rowwise ( ) const
inline
Returns
a VectorwiseOp wrapper of *this providing additional partial reduction operations

Example:

cout << "Here is the matrix m:" << endl << m << endl;
cout << "Here is the sum of each row:" << endl << m.rowwise().sum() << endl;
cout << "Here is the maximum absolute value of each row:"
<< endl << m.cwiseAbs().rowwise().maxCoeff() << endl;

Output:

Here is the matrix m:
  0.68  0.597  -0.33
-0.211  0.823  0.536
 0.566 -0.605 -0.444
Here is the sum of each row:
 0.948
  1.15
-0.483
Here is the maximum absolute value of each row:
 0.68
0.823
0.605
See Also
colwise(), class VectorwiseOp, Reductions, visitors and broadcasting

Referenced by Eigen::umeyama().

DenseBase< Derived >::RowwiseReturnType rowwise ( )
inline
Returns
a writable VectorwiseOp wrapper of *this providing additional partial reduction operations
See Also
colwise(), class VectorwiseOp, Reductions, visitors and broadcasting
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:

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:

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).

const Select< Derived, ThenDerived, ElseDerived > select ( const DenseBase< ThenDerived > &  thenMatrix,
const DenseBase< ElseDerived > &  elseMatrix 
) const
inline
Returns
a matrix where each coefficient (i,j) is equal to thenMatrix(i,j) if *this(i,j), and elseMatrix(i,j) otherwise.

Example:

MatrixXi m(3, 3);
m << 1, 2, 3,
4, 5, 6,
7, 8, 9;
m = (m.array() >= 5).select(-m, m);
cout << m << endl;

Output:

 1  2  3
 4 -5 -6
-7 -8 -9
See Also
class Select
const Select< Derived, ThenDerived, typename ThenDerived::ConstantReturnType > select ( const DenseBase< ThenDerived > &  thenMatrix,
const typename ThenDerived::Scalar &  elseScalar 
) const
inline

Version of DenseBase::select(const DenseBase&, const DenseBase&) with the else expression being a scalar value.

See Also
DenseBase::select(const DenseBase<ThenDerived>&, const DenseBase<ElseDerived>&) const, class Select
const Select< Derived, typename ElseDerived::ConstantReturnType, ElseDerived > select ( const typename ElseDerived::Scalar &  thenScalar,
const DenseBase< ElseDerived > &  elseMatrix 
) const
inline

Version of DenseBase::select(const DenseBase&, const DenseBase&) with the then expression being a scalar value.

See Also
DenseBase::select(const DenseBase<ThenDerived>&, const DenseBase<ElseDerived>&) const, class Select
Derived & setConstant ( const Scalar &  val)
inline

Sets all coefficients in this expression to value.

See Also
fill(), setConstant(Index,const Scalar&), setConstant(Index,Index,const Scalar&), setZero(), setOnes(), Constant(), class CwiseNullaryOp, setZero(), setOnes()
Derived & setLinSpaced ( Index  newSize,
const Scalar &  low,
const Scalar &  high 
)
inline

Sets a linearly space vector.

The function generates 'size' equally spaced values in the closed interval [low,high]. When size is set to 1, a vector of length 1 containing 'high' is returned.

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.

Example:

VectorXf v;
v.setLinSpaced(5,0.5f,1.5f);
cout << v << endl;

Output:

 0.5
0.75
   1
1.25
 1.5
See Also
CwiseNullaryOp
Derived & setLinSpaced ( const Scalar &  low,
const Scalar &  high 
)
inline

Sets a linearly space vector.

The function fill *this with equally spaced values in the closed interval [low,high]. When size is set to 1, a vector of length 1 containing 'high' is returned.

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.

See Also
setLinSpaced(Index, const Scalar&, const Scalar&), CwiseNullaryOp
Derived & setOnes ( )
inline

Sets all coefficients in this expression to one.

Example:

m.row(1).setOnes();
cout << m << endl;

Output:

 7  9 -5 -3
 1  1  1  1
 6 -3  0  9
 6  6  3  9
See Also
class CwiseNullaryOp, Ones()
Derived & setRandom ( )
inline

Sets all coefficients in this expression to random values.

Numbers are uniformly spread through their whole definition range for integer types, and in the [-1:1] range for floating point scalar types.

Warning
This function is not re-entrant.

Example:

m.col(1).setRandom();
cout << m << endl;

Output:

 0  7  0  0
 0 -2  0  0
 0  6  0  0
 0  6  0  0
See Also
class CwiseNullaryOp, setRandom(Index), setRandom(Index,Index)
Derived & setZero ( )
inline

Sets all coefficients in this expression to zero.

Example:

m.row(1).setZero();
cout << m << endl;

Output:

 7  9 -5 -3
 0  0  0  0
 6 -3  0  9
 6  6  3  9
See Also
class CwiseNullaryOp, Zero()
internal::traits< Derived >::Scalar sum ( ) const
inline
Returns
the sum of all coefficients of *this
See Also
trace(), prod(), mean()

References Eigen::Dynamic.

void swap ( const DenseBase< OtherDerived > &  other,
int  = OtherDerived::ThisConstantIsPrivateInPlainObjectBase 
)
inline

swaps *this with the expression other.

void swap ( PlainObjectBase< OtherDerived > &  other)
inline

swaps *this with the matrix or array other.

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:

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:

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:

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:

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:

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:

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:

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:

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>().

Transpose< Derived > transpose ( )
inline
Returns
an expression of the transpose of *this.

Example:

cout << "Here is the matrix m:" << endl << m << endl;
cout << "Here is the transpose of m:" << endl << m.transpose() << endl;
cout << "Here is the coefficient (1,0) in the transpose of m:" << endl
<< m.transpose()(1,0) << endl;
cout << "Let us overwrite this coefficient with the value 0." << endl;
m.transpose()(1,0) = 0;
cout << "Now the matrix m is:" << endl << m << endl;

Output:

Here is the matrix m:
 7  6
-2  6
Here is the transpose of m:
 7 -2
 6  6
Here is the coefficient (1,0) in the transpose of m:
6
Let us overwrite this coefficient with the value 0.
Now the matrix m is:
 7  0
-2  6
Warning
If you want to replace a matrix by its own transpose, do NOT do this:
* m = m.transpose(); // bug!!! caused by aliasing effect
*
Instead, use the transposeInPlace() method:
* m.transposeInPlace();
*
which gives Eigen good opportunities for optimization, or alternatively you can also do:
* m = m.transpose().eval();
*
See Also
transposeInPlace(), adjoint()
DenseBase< Derived >::ConstTransposeReturnType transpose ( ) const
inline

This is the const version of transpose().

Make sure you read the warning for transpose() !

See Also
transposeInPlace(), adjoint()
void transposeInPlace ( )
inline

This is the "in place" version of transpose(): it replaces *this by its own transpose. Thus, doing

* m.transposeInPlace();
*

has the same effect on m as doing

* m = m.transpose().eval();
*

and is faster and also safer because in the latter line of code, forgetting the eval() results in a bug caused by aliasing.

Notice however that this method is only useful if you want to replace a matrix by its own transpose. If you just need the transpose of a matrix, use transpose().

Note
if the matrix is not square, then *this must be a resizable matrix. This excludes (non-square) fixed-size matrices, block-expressions and maps.
See Also
transpose(), adjoint(), adjointInPlace()

References Eigen::Dynamic.

CoeffReturnType value ( ) const
inline
Returns
the unique coefficient of a 1x1 expression
void visit ( Visitor &  visitor) const

Applies the visitor visitor to the whole coefficients of the matrix or vector.

The template parameter Visitor is the type of the visitor and provides the following interface:

* struct MyVisitor {
* // called for the first coefficient
* void init(const Scalar& value, Index i, Index j);
* // called for all other coefficients
* void operator() (const Scalar& value, Index i, Index j);
* };
*
Note
compared to one or two for loops, visitors offer automatic unrolling for small fixed size matrix.
See Also
minCoeff(Index*,Index*), maxCoeff(Index*,Index*), DenseBase::redux()

References Eigen::Dynamic.

const DenseBase< Derived >::ConstantReturnType Zero ( Index  nbRows,
Index  nbCols 
)
inlinestatic
Returns
an expression of a zero matrix.

The parameters rows and cols are the number of rows and of columns of the returned matrix. Must be compatible with this MatrixBase type.

This variant is meant to be used for dynamic-size matrix types. For fixed-size types, it is redundant to pass rows and cols as arguments, so Zero() should be used instead.

Example:

cout << MatrixXi::Zero(2,3) << endl;

Output:

0 0 0
0 0 0
See Also
Zero(), Zero(Index)
const DenseBase< Derived >::ConstantReturnType Zero ( Index  size)
inlinestatic
Returns
an expression of a zero vector.

The parameter size is the size of the returned vector. Must be compatible with this MatrixBase type.

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.

This variant is meant to be used for dynamic-size vector types. For fixed-size types, it is redundant to pass size as argument, so Zero() should be used instead.

Example:

cout << RowVectorXi::Zero(4) << endl;
cout << VectorXf::Zero(2) << endl;

Output:

0 0 0 0
0
0
See Also
Zero(), Zero(Index,Index)
const DenseBase< Derived >::ConstantReturnType Zero ( )
inlinestatic
Returns
an expression of a fixed-size zero matrix or vector.

This variant is only for fixed-size MatrixBase types. For dynamic-size types, you need to use the variants taking size arguments.

Example:

cout << Matrix2d::Zero() << endl;
cout << RowVector4i::Zero() << endl;

Output:

0 0
0 0
0 0 0 0
See Also
Zero(Index), Zero(Index,Index)

Friends And Related Function Documentation

std::ostream & operator<< ( std::ostream &  s,
const DenseBase< Derived > &  m 
)
related

Outputs the matrix, to the given stream.

If you wish to print the matrix with a format different than the default, use DenseBase::format().

It is also possible to change the default format by defining EIGEN_DEFAULT_IO_FORMAT before including Eigen headers. If not defined, this will automatically be defined to Eigen::IOFormat(), that is the Eigen::IOFormat with default parameters.

See Also
DenseBase::format()

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