Eigen  3.4.90 (git rev 67eeba6e720c5745abc77ae6c92ce0a44aa7b7ae)
Eigen::Reshaped< XprType, Rows, Cols, Order > Class Template Reference

## Detailed Description

### template<typename XprType, int Rows, int Cols, int Order> class Eigen::Reshaped< XprType, Rows, Cols, Order >

Expression of a fixed-size or dynamic-size reshape.

Template Parameters
 XprType the type of the expression in which we are taking a reshape Rows the number of rows of the reshape we are taking at compile time (optional) Cols the number of columns of the reshape we are taking at compile time (optional) Order can be ColMajor or RowMajor, default is ColMajor.

This class represents an expression of either a fixed-size or dynamic-size reshape. It is the return type of DenseBase::reshaped(NRowsType,NColsType) and most of the time this is the only way it is used.

If you want to directly manipulate reshaped expressions, for instance if you want to write a function returning such an expression, it is advised to use the auto keyword for such use cases.

Here is an example illustrating the dynamic case:

#include <Eigen/Core>
#include <iostream>
template<typename Derived>
reshape_helper(const Eigen::MatrixBase<Derived>& m, int rows, int cols)
{
return Eigen::Reshaped<const Derived>(m.derived(), rows, cols);
}
int main(int, char**)
{
Eigen::MatrixXd m(3, 4);
m << 1, 4, 7, 10,
2, 5, 8, 11,
3, 6, 9, 12;
std::cout << m << std::endl;
Eigen::Ref<const Eigen::MatrixXd> n = reshape_helper(m, 2, 6);
std::cout << "Matrix m is:" << std::endl << m << std::endl;
std::cout << "Matrix n is:" << std::endl << n << std::endl;
}
Derived & derived()
Definition: EigenBase.h:48
Base class for all dense matrices, vectors, and expressions.
Definition: MatrixBase.h:52
The matrix class, also used for vectors and row-vectors.
Definition: Matrix.h:182
A matrix or vector expression mapping an existing expression.
Definition: Ref.h:285
Expression of a fixed-size or dynamic-size reshape.
Definition: Reshaped.h:99

Output:

 1  4  7 10
2  5  8 11
3  6  9 12
Matrix m is:
1  4  7 10
2  5  8 11
3  6  9 12
Matrix n is:
1  3  5  7  9 11
2  4  6  8 10 12


Here is an example illustrating the fixed-size case:

#include <Eigen/Core>
#include <iostream>
template<typename Derived>
reshape_helper(Eigen::MatrixBase<Derived>& m)
{
}
int main(int, char**)
{
Eigen::MatrixXd m(2, 4);
m << 1, 2, 3, 4,
5, 6, 7, 8;
Eigen::MatrixXd n = reshape_helper(m);
std::cout << "matrix m is:" << std::endl << m << std::endl;
std::cout << "matrix n is:" << std::endl << n << std::endl;
return 0;
}

Output:

matrix m is:
1 2 3 4
5 6 7 8
matrix n is:
1 3
5 7
2 4
6 8

DenseBase::reshaped(NRowsType,NColsType)

Inherits Eigen::ReshapedImpl< XprType, Rows, Cols, Order, internal::traits< XprType >::StorageKind >.

## Public Member Functions

Reshaped (XprType &xpr)

Reshaped (XprType &xpr, Index reshapeRows, Index reshapeCols)

## ◆ Reshaped() [1/2]

template<typename XprType , int Rows, int Cols, int Order>
 Eigen::Reshaped< XprType, Rows, Cols, Order >::Reshaped ( XprType & xpr )
inline

Fixed-size constructor

## ◆ Reshaped() [2/2]

template<typename XprType , int Rows, int Cols, int Order>
 Eigen::Reshaped< XprType, Rows, Cols, Order >::Reshaped ( XprType & xpr, Index reshapeRows, Index reshapeCols )
inline

Dynamic-size constructor

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