Eigen::VectorwiseOp Class Reference

Detailed Description

Pseudo expression providing partial reduction operations.

Template Parameters

ExpressionType	the type of the object on which to do partial reductions
Direction	indicates the direction of the redux (Vertical or Horizontal)

This class represents a pseudo expression with partial reduction features. It is the return type of DenseBase::colwise() and DenseBase::rowwise() and most of the time this is the only way it is used.

Example:

Matrix3d m = Matrix3d::Random();
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

DenseBase::colwise(), DenseBase::rowwise(), class PartialReduxExpr

Public Types
typedef Eigen::Index	Index

Public Member Functions
const AllReturnType	all () const
const AnyReturnType	any () const
const BlueNormReturnType	blueNorm () const
const CountReturnType	count () const
template<typename OtherDerived >
const CrossReturnType	cross (const MatrixBase< OtherDerived > &other) const
const HNormalizedReturnType	hnormalized () const
	column or row-wise homogeneous normalization More...
HomogeneousReturnType	homogeneous () const
const HypotNormReturnType	hypotNorm () const
template<int p>
const LpNormReturnType< p >::Type	lpNorm () const
const MaxCoeffReturnType	maxCoeff () const
const MeanReturnType	mean () const
const MinCoeffReturnType	minCoeff () const
const NormReturnType	norm () const
void	normalize ()
CwiseBinaryOp< internal::scalar_quotient_op< Scalar >, const ExpressionTypeNestedCleaned, const typename OppositeExtendedType< typename ReturnType< internal::member_norm, RealScalar >::Type >::Type >	normalized () const
template<typename OtherDerived >
CwiseBinaryOp< internal::scalar_product_op< Scalar >, const ExpressionTypeNestedCleaned, const typename ExtendedType< OtherDerived >::Type >	operator* (const DenseBase< OtherDerived > &other) const
template<typename OtherDerived >
ExpressionType &	operator*= (const DenseBase< OtherDerived > &other)
template<typename OtherDerived >
CwiseBinaryOp< internal::scalar_sum_op< Scalar, typename OtherDerived::Scalar >, const ExpressionTypeNestedCleaned, const typename ExtendedType< OtherDerived >::Type >	operator+ (const DenseBase< OtherDerived > &other) const
template<typename OtherDerived >
ExpressionType &	operator+= (const DenseBase< OtherDerived > &other)
template<typename OtherDerived >
CwiseBinaryOp< internal::scalar_difference_op< Scalar, typename OtherDerived::Scalar >, const ExpressionTypeNestedCleaned, const typename ExtendedType< OtherDerived >::Type >	operator- (const DenseBase< OtherDerived > &other) const
template<typename OtherDerived >
ExpressionType &	operator-= (const DenseBase< OtherDerived > &other)
template<typename OtherDerived >
CwiseBinaryOp< internal::scalar_quotient_op< Scalar >, const ExpressionTypeNestedCleaned, const typename ExtendedType< OtherDerived >::Type >	operator/ (const DenseBase< OtherDerived > &other) const
template<typename OtherDerived >
ExpressionType &	operator/= (const DenseBase< OtherDerived > &other)
template<typename OtherDerived >
ExpressionType &	operator= (const DenseBase< OtherDerived > &other)
const ProdReturnType	prod () const
template<typename BinaryOp >
const ReduxReturnType< BinaryOp >::Type	redux (const BinaryOp &func=BinaryOp()) const
const ReplicateReturnType	replicate (Index factor) const
template<int Factor>
const Replicate< ExpressionType, isVertical *Factor+isHorizontal, isHorizontal *Factor+isVertical >	replicate (Index factor=Factor) const
ReverseReturnType	reverse ()
const ConstReverseReturnType	reverse () const
void	reverseInPlace ()
const SquaredNormReturnType	squaredNorm () const
const StableNormReturnType	stableNorm () const
const SumReturnType	sum () const

Member Typedef Documentation

Index

typedef Eigen::Index Eigen::VectorwiseOp::Index

Deprecated:

since Eigen 3.3

Member Function Documentation

all()

const AllReturnType Eigen::VectorwiseOp::all ( ) const

inline

Returns

a row (or column) vector expression representing whether all coefficients of each respective column (or row) are true. This expression can be assigned to a vector with entries of type bool.

See also

DenseBase::all()

any()

const AnyReturnType Eigen::VectorwiseOp::any ( ) const

inline

Returns

a row (or column) vector expression representing whether at least one coefficient of each respective column (or row) is true. This expression can be assigned to a vector with entries of type bool.

See also

DenseBase::any()

blueNorm()

const BlueNormReturnType Eigen::VectorwiseOp::blueNorm ( ) const

inline

Returns

a row (or column) vector expression of the norm of each column (or row) of the referenced expression, using Blue's algorithm. This is a vector with real entries, even if the original matrix has complex entries.

See also

DenseBase::blueNorm()

count()

const CountReturnType Eigen::VectorwiseOp::count ( ) const

inline

Returns

a row (or column) vector expression representing the number of true coefficients of each respective column (or row). This expression can be assigned to a vector whose entries have the same type as is used to index entries of the original matrix; for dense matrices, this is std::ptrdiff_t .

Example:

Matrix3d m = Matrix3d::Random();
cout << "Here is the matrix m:" << endl << m << endl;
Matrix<ptrdiff_t, 3, 1> res = (m.array() >= 0.5).rowwise().count();
cout << "Here is the count of elements larger or equal than 0.5 of each row:" << endl;
cout << res << 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 count of elements larger or equal than 0.5 of each row:
2
2
1

See also

DenseBase::count()

hypotNorm()

const HypotNormReturnType Eigen::VectorwiseOp::hypotNorm ( ) const

inline

Returns

a row (or column) vector expression of the norm of each column (or row) of the referenced expression, avoiding underflow and overflow using a concatenation of hypot() calls. This is a vector with real entries, even if the original matrix has complex entries.

See also

DenseBase::hypotNorm()

lpNorm()

template<int p>

const LpNormReturnType<p>::Type Eigen::VectorwiseOp::lpNorm ( ) const

inline

Returns

a row (or column) vector expression of the norm of each column (or row) of the referenced expression. This is a vector with real entries, even if the original matrix has complex entries.

Example:

Matrix3d m = Matrix3d::Random();
cout << "Here is the matrix m:" << endl << m << endl;
cout << "Here is the norm of each column:" << endl << m.colwise().norm() << 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 norm of each column:
 0.91  1.18 0.771

See also

DenseBase::norm()

maxCoeff()

const MaxCoeffReturnType Eigen::VectorwiseOp::maxCoeff ( ) const

inline

Returns

a row (or column) vector expression of the largest coefficient of each column (or row) of the referenced expression.

Warning

the result is undefined if *this contains NaN.

Example:

Matrix3d m = Matrix3d::Random();
cout << "Here is the matrix m:" << endl << m << endl;
cout << "Here is the maximum of each column:" << endl << m.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 maximum of each column:
 0.68 0.823 0.536

See also

DenseBase::maxCoeff()

mean()

const MeanReturnType Eigen::VectorwiseOp::mean ( ) const

inline

Returns

a row (or column) vector expression of the mean of each column (or row) of the referenced expression.

See also

DenseBase::mean()

minCoeff()

const MinCoeffReturnType Eigen::VectorwiseOp::minCoeff ( ) const

inline

Returns

a row (or column) vector expression of the smallest coefficient of each column (or row) of the referenced expression.

Warning

the result is undefined if *this contains NaN.

Example:

Matrix3d m = Matrix3d::Random();
cout << "Here is the matrix m:" << endl << m << endl;
cout << "Here is the minimum of each column:" << endl << m.colwise().minCoeff() << 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 minimum of each column:
-0.211 -0.605 -0.444

See also

DenseBase::minCoeff()

norm()

const NormReturnType Eigen::VectorwiseOp::norm ( ) const

inline

Returns

a row (or column) vector expression of the norm of each column (or row) of the referenced expression. This is a vector with real entries, even if the original matrix has complex entries.

Example:

Matrix3d m = Matrix3d::Random();
cout << "Here is the matrix m:" << endl << m << endl;
cout << "Here is the norm of each column:" << endl << m.colwise().norm() << 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 norm of each column:
 0.91  1.18 0.771

See also

DenseBase::norm()

normalize()

void Eigen::VectorwiseOp::normalize ( )

inline

Normalize in-place each row or columns of the referenced matrix.

See also

MatrixBase::normalize(), normalized()

normalized()

CwiseBinaryOp<internal::scalar_quotient_op<Scalar>, const ExpressionTypeNestedCleaned, const typename OppositeExtendedType<typename ReturnType<internal::member_norm,RealScalar>::Type>::Type> Eigen::VectorwiseOp::normalized ( ) const

inline

Returns

an expression where each column (or row) of the referenced matrix are normalized. The referenced matrix is not modified.

See also

MatrixBase::normalized(), normalize()

operator*()

template<typename OtherDerived >

CwiseBinaryOp<internal::scalar_product_op<Scalar>, const ExpressionTypeNestedCleaned, const typename ExtendedType<OtherDerived>::Type> Eigen::VectorwiseOp::operator* ( const DenseBase< OtherDerived > &  other ) const

inline

Returns the expression where each subvector is the product of the vector other by the corresponding subvector of *this

operator*=()

template<typename OtherDerived >

ExpressionType& Eigen::VectorwiseOp::operator*= ( const DenseBase< OtherDerived > &  other )

inline

Multiples each subvector of *this by the vector other

operator+()

template<typename OtherDerived >

CwiseBinaryOp<internal::scalar_sum_op<Scalar,typename OtherDerived::Scalar>, const ExpressionTypeNestedCleaned, const typename ExtendedType<OtherDerived>::Type> Eigen::VectorwiseOp::operator+ ( const DenseBase< OtherDerived > &  other ) const

inline

Returns the expression of the sum of the vector other to each subvector of *this

operator+=()

template<typename OtherDerived >

ExpressionType& Eigen::VectorwiseOp::operator+= ( const DenseBase< OtherDerived > &  other )

inline

Adds the vector other to each subvector of *this

operator-()

template<typename OtherDerived >

CwiseBinaryOp<internal::scalar_difference_op<Scalar,typename OtherDerived::Scalar>, const ExpressionTypeNestedCleaned, const typename ExtendedType<OtherDerived>::Type> Eigen::VectorwiseOp::operator- ( const DenseBase< OtherDerived > &  other ) const

inline

Returns the expression of the difference between each subvector of *this and the vector other

operator-=()

template<typename OtherDerived >

ExpressionType& Eigen::VectorwiseOp::operator-= ( const DenseBase< OtherDerived > &  other )

inline

Substracts the vector other to each subvector of *this

operator/()

template<typename OtherDerived >

CwiseBinaryOp<internal::scalar_quotient_op<Scalar>, const ExpressionTypeNestedCleaned, const typename ExtendedType<OtherDerived>::Type> Eigen::VectorwiseOp::operator/ ( const DenseBase< OtherDerived > &  other ) const

inline

Returns the expression where each subvector is the quotient of the corresponding subvector of *this by the vector other

operator/=()

template<typename OtherDerived >

ExpressionType& Eigen::VectorwiseOp::operator/= ( const DenseBase< OtherDerived > &  other )

inline

Divides each subvector of *this by the vector other

operator=()

template<typename OtherDerived >

ExpressionType& Eigen::VectorwiseOp::operator= ( const DenseBase< OtherDerived > &  other )

inline

Copies the vector other to each subvector of *this

prod()

const ProdReturnType Eigen::VectorwiseOp::prod ( ) const

inline

Returns

a row (or column) vector expression of the product of each column (or row) of the referenced expression.

Example:

Matrix3d m = Matrix3d::Random();
cout << "Here is the matrix m:" << endl << m << endl;
cout << "Here is the product of each row:" << endl << m.rowwise().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 each row:
 -0.134
-0.0933
  0.152

See also

DenseBase::prod()

redux()

template<typename BinaryOp >

const ReduxReturnType<BinaryOp>::Type Eigen::VectorwiseOp::redux ( const BinaryOp &  func = BinaryOp() ) const

inline

Returns

a row or column vector expression of *this reduxed by func

The template parameter BinaryOp is the type of the functor of the custom redux operator. Note that func must be an associative operator.

See also

class VectorwiseOp, DenseBase::colwise(), DenseBase::rowwise()

replicate() [1/2]

const VectorwiseOp< ExpressionType, Direction >::ReplicateReturnType Eigen::VectorwiseOp::replicate

(

Index

factor

)

const

Returns

an expression of the replication of each column (or row) of *this

Example:

Vector3i v = Vector3i::Random();
cout << "Here is the vector v:" << endl << v << endl;
cout << "v.rowwise().replicate(5) = ..." << endl;
cout << v.rowwise().replicate(5) << endl;

Output:

Here is the vector v:
 7
-2
 6
v.rowwise().replicate(5) = ...
 7  7  7  7  7
-2 -2 -2 -2 -2
 6  6  6  6  6

See also

VectorwiseOp::replicate(), DenseBase::replicate(), class Replicate

replicate() [2/2]

template<int Factor>

const Replicate<ExpressionType,isVertical*Factor+isHorizontal,isHorizontal*Factor+isVertical> Eigen::VectorwiseOp::replicate ( Index  factor = Factor ) const

inline

Returns

an expression of the replication of each column (or row) of *this

Example:

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

Output:

Here is the matrix m:
 7  6  9
-2  6 -6
m.colwise().replicate<3>() = ...
 7  6  9
-2  6 -6
 7  6  9
-2  6 -6
 7  6  9
-2  6 -6

See also

VectorwiseOp::replicate(Index), DenseBase::replicate(), class Replicate

reverse() [1/2]

ReverseReturnType Eigen::VectorwiseOp::reverse ( )

inline

Returns

a writable matrix expression where each column (or row) are reversed.

See also

reverse() const

reverse() [2/2]

const ConstReverseReturnType Eigen::VectorwiseOp::reverse ( ) const

inline

Returns

a matrix expression where each column (or row) are reversed.

Example:

MatrixXi m = MatrixXi::Random(3,4);
cout << "Here is the matrix m:" << endl << m << endl;
cout << "Here is the rowwise reverse of m:" << endl << m.rowwise().reverse() << endl;
cout << "Here is the colwise reverse of m:" << endl << m.colwise().reverse() << endl;
 
cout << "Here is the coefficient (1,0) in the rowise reverse of m:" << endl
<< m.rowwise().reverse()(1,0) << endl;
cout << "Let us overwrite this coefficient with the value 4." << endl;
//m.colwise().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 rowwise reverse of m:
 1 -3  6  7
 0  6  9 -2
 3 -5 -6  6
Here is the colwise reverse of m:
 6 -6 -5  3
-2  9  6  0
 7  6 -3  1
Here is the coefficient (1,0) in the rowise 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  0
 6 -6 -5  3

See also

DenseBase::reverse()

reverseInPlace()

void Eigen::VectorwiseOp::reverseInPlace ( )

inline

This is the "in place" version of VectorwiseOp::reverse: it reverses each column or row of *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 benefits:

• less error prone: doing the same operation with .reverse() requires special care:

  m = m.reverse().eval(); 

• this API enables reverse operations without the need for a temporary

See also

DenseBase::reverseInPlace(), reverse()

squaredNorm()

const SquaredNormReturnType Eigen::VectorwiseOp::squaredNorm ( ) const

inline

Returns

a row (or column) vector expression of the squared norm of each column (or row) of the referenced expression. This is a vector with real entries, even if the original matrix has complex entries.

Example:

Matrix3d m = Matrix3d::Random();
cout << "Here is the matrix m:" << endl << m << endl;
cout << "Here is the square norm of each row:" << endl << m.rowwise().squaredNorm() << 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 square norm of each row:
0.928
 1.01
0.884

See also

DenseBase::squaredNorm()

stableNorm()

const StableNormReturnType Eigen::VectorwiseOp::stableNorm ( ) const

inline

Returns

a row (or column) vector expression of the norm of each column (or row) of the referenced expression, avoiding underflow and overflow. This is a vector with real entries, even if the original matrix has complex entries.

See also

DenseBase::stableNorm()

sum()

const SumReturnType Eigen::VectorwiseOp::sum ( ) const

inline

Returns

a row (or column) vector expression of the sum of each column (or row) of the referenced expression.

Example:

Matrix3d m = Matrix3d::Random();
cout << "Here is the matrix m:" << endl << m << endl;
cout << "Here is the sum of each row:" << endl << m.rowwise().sum() << 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

See also

DenseBase::sum()

---

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

• ForwardDeclarations.h
• VectorwiseOp.h
• Replicate.h
• Reverse.h
• Homogeneous.h
• OrthoMethods.h