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add transposeInPlace (not optimized yet for rectangular matrix)

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This commit is contained in:
Gael Guennebaud
2008-10-29 15:24:08 +00:00
parent 48137e28d8
commit ebe14aae7d
4 changed files with 66 additions and 6 deletions
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45
Eigen/src/Core/Transpose.h
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@@ -156,4 +156,49 @@ MatrixBase<Derived>::adjoint() const
return conjugate().nestByValue();
}
/***************************************************************************
* "in place" transpose implementation
***************************************************************************/
template<typename MatrixType,
bool IsSquare = (MatrixType::RowsAtCompileTime == MatrixType::ColsAtCompileTime) && MatrixType::RowsAtCompileTime!=Dynamic>
struct ei_inplace_transpose_selector;
template<typename MatrixType>
struct ei_inplace_transpose_selector<MatrixType,true> { // square matrix
static void run(MatrixType& m) {
m.template part<StrictlyUpper>().swap(m.transpose());
}
};
template<typename MatrixType>
struct ei_inplace_transpose_selector<MatrixType,false> { // non square matrix
static void run(MatrixType& m) {
if (m.rows()==m.cols())
m.template part<StrictlyUpper>().swap(m.transpose());
else
m.set(m.transpose().eval());
}
};
/** This is the "in place" version of transpose: it transposes \c *this.
*
* In most cases it is probably better to simply use the transposed expression
* of a matrix. However, when transposing 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 .transpose() requires special care:
* \code m.set(m.transpose().eval()); \endcode
* - no temporary object is created (currently only for squared matrices)
* - it allows future optimizations (cache friendliness, etc.)
*
* \note if the matrix is not square, then \c *this must be a resizable matrix.
*
* \sa transpose(), adjoint() */
template<typename Derived>
inline void MatrixBase<Derived>::transposeInPlace()
{
ei_inplace_transpose_selector<Derived>::run(derived());
}
#endif // EIGEN_TRANSPOSE_H