-/* -*- C++ -*- ------------------------------------------------------------
-
-Copyright (c) 2007 Jesse Anders and Demian Nave http://cmldev.net/
-
-The Configurable Math Library (CML) is distributed under the terms of the
-Boost Software License, v1.0 (see cml/LICENSE for details).
-
- *-----------------------------------------------------------------------*/
-/** @file
- * @brief
- *
- * @todo Currently, the transpose() and T() functions copy the transposed
- * result into a temporary, and return it to avoid aliasing problems, e.g.
- * C = transpose(C). By checking for C on the right-hand side, this can
- * be avoided, but experimentation is needed to determine the impact on
- * performance. Another option is to use a function to explicitly specify
- * when a temporary is needed; e.g. C = transpose(temp(C)).
- */
-
-#ifndef matrix_transpose_h
-#define matrix_transpose_h
-
-#include <cml/matrix/matrix_expr.h>
-
-#define MATRIX_TRANSPOSE_RETURNS_TEMP
-
-namespace cml {
-namespace et {
-
-/** "Transpose" the given matrix expression.
- *
- * This does nothing more than change the result type of the expression
- * into one with the opposite orientation (i.e. row->col, col->row).
- */
-template<class ExprT>
-class MatrixTransposeOp
-{
- public:
-
- typedef MatrixTransposeOp<ExprT> expr_type;
-
- /* Record ary-ness of the expression: */
- typedef unary_expression expr_ary;
-
- /* Copy the expression by value into higher-up expressions: */
- typedef expr_type expr_const_reference;
-
- typedef typename ExprT::value_type value_type;
- typedef matrix_result_tag result_tag;
- typedef typename ExprT::size_tag size_tag;
-
- /* Store the expression traits: */
- typedef ExprTraits<ExprT> expr_traits;
-
- /* Get the reference type: */
- typedef typename expr_traits::const_reference expr_reference;
-
- /* Swap the orientation: */
- typedef typename expr_traits::result_type::transposed_type result_type;
-
- /* Get the temporary type: */
- typedef typename result_type::temporary_type temporary_type;
-
- /* For matching by assignability: */
- typedef cml::et::not_assignable_tag assignable_tag;
-
-
- public:
-
- /** Record result size as an enum. */
- enum {
- array_rows = result_type::array_rows,
- array_cols = result_type::array_cols
- };
-
-
- public:
-
- /** Return the expression size as a pair. */
- matrix_size size() const {
- return matrix_size(this->rows(),this->cols());
- }
-
- /** Return result rows.
- *
- * The tranpose has the same number of rows as the original has
- * columns.
- */
- size_t rows() const {
- return expr_traits().cols(m_expr);
- }
-
- /** Return result cols.
- *
- * The tranpose has the same number of columns as the original has
- * rows.
- */
- size_t cols() const {
- return expr_traits().rows(m_expr);
- }
-
- /** Return reference to contained expression. */
- expr_reference expression() const { return m_expr; }
-
- /** Compute value at index i of the result matrix.
- *
- * Element (i,j) of the transpose is element (j,i) of the original
- * expression.
- */
- value_type operator()(size_t i, size_t j) const {
- return expr_traits().get(m_expr,j,i);
- }
-
-
- public:
-
- /** Construct from the subexpression to store. */
- explicit MatrixTransposeOp(const ExprT& expr) : m_expr(expr) {}
-
- /** Copy constructor. */
- MatrixTransposeOp(const expr_type& e) : m_expr(e.m_expr) {}
-
-
- protected:
-
- expr_reference m_expr;
-
-
- private:
-
- /* Cannot be assigned to: */
- expr_type& operator=(const expr_type&);
-};
-
-/** Expression traits class for VectorTransposeOp<>. */
-template<class ExprT>
-struct ExprTraits< MatrixTransposeOp<ExprT> >
-{
- typedef MatrixTransposeOp<ExprT> expr_type;
- typedef typename expr_type::value_type value_type;
- typedef typename expr_type::expr_const_reference const_reference;
- typedef typename expr_type::result_tag result_tag;
- typedef typename expr_type::size_tag size_tag;
- typedef typename expr_type::result_type result_type;
- typedef typename expr_type::assignable_tag assignable_tag;
- typedef expr_node_tag node_tag;
-
- value_type get(const expr_type& m, size_t i, size_t j) const {
- return m(i,j);
- }
-
- matrix_size size(const expr_type& e) const { return e.size(); }
- size_t rows(const expr_type& e) const { return e.rows(); }
- size_t cols(const expr_type& e) const { return e.cols(); }
-};
-
-} // namespace et
-
-
-/* Define the transpose operators in the cml namespace: */
-#if defined(MATRIX_TRANSPOSE_RETURNS_TEMP)
-
-/** Matrix transpose operator taking a matrix operand. */
-template<typename E, class AT, typename BO, typename L>
-typename et::MatrixTransposeOp<
- matrix<E,AT,BO,L>
->::temporary_type
-transpose(const matrix<E,AT,BO,L>& expr)
-{
- /* Record the matrix type: */
- typedef matrix<E,AT,BO,L> matrix_type;
-
- /* Record the type of the transpose op: */
- typedef et::MatrixTransposeOp<matrix_type> Op;
-
- /* Determine the returned matrix type: */
- typedef typename et::MatrixTransposeOp<
- matrix_type
- >::temporary_type tmp_type;
-
- /* The expression to use to assign the temporary: */
- typedef et::MatrixXpr<Op> ExprT;
-
- /* Create the temporary and return it: */
- tmp_type tmp;
- cml::et::detail::Resize(tmp,expr.rows(),expr.cols());
- tmp = ExprT(Op(expr));
- return tmp;
-}
-
-/** Matrix transpose operator taking an et::MatrixXpr operand.
- *
- * The parse tree is automatically compressed by hoisting the MatrixXpr's
- * subexpression into the subexpression of the MatrixTransposeOp.
- */
-template<class XprT>
-typename et::MatrixTransposeOp<
- XprT
->::temporary_type
-transpose(MATXPR_ARG_TYPE expr)
-{
- /* Record the type of the transpose op: */
- typedef et::MatrixTransposeOp<XprT> Op;
-
- /* Determine the returned matrix type: */
- typedef typename et::MatrixTransposeOp<XprT>::temporary_type tmp_type;
-
- /* The expression to use to assign the temporary: */
- typedef et::MatrixXpr<Op> ExprT;
-
- /* Create the temporary and return it: */
- tmp_type tmp;
- cml::et::detail::Resize(tmp,expr.rows(),expr.cols());
- tmp = ExprT(Op(expr.expression()));
- return tmp;
-}
-
-
-/* For notational convenience: */
-
-/** Matrix transpose operator taking a matrix operand. */
-template<typename E, class AT, typename BO, typename L>
-typename et::MatrixTransposeOp<
- matrix<E,AT,BO,L>
->::temporary_type
-T(const matrix<E,AT,BO,L>& expr)
-{
- return transpose(expr);
-}
-
-/** Matrix transpose operator taking an et::MatrixXpr operand.
- *
- * The parse tree is automatically compressed by hoisting the MatrixXpr's
- * subexpression into the subexpression of the MatrixTransposeOp.
- */
-template<class XprT>
-typename et::MatrixTransposeOp<
- XprT
->::temporary_type
-T(MATXPR_ARG_TYPE expr)
-{
- return transpose(expr);
-}
-
-#else
-
-/* XXX For this to work correctly, matrix assignment and copy have to be
- * changed to either use a temporary all the time, or to create a temporary
- * when the same matrix appears on both sides of an assignment, and a
- * temporary was not already created on the RHS by the ET code.
- */
-
-/** Matrix transpose operator taking a matrix operand. */
-template<typename E, class AT, typename BO, typename L>
-et::MatrixXpr< et::MatrixTransposeOp< matrix<E,AT,BO,L> > >
-transpose(const matrix<E,AT,BO,L>& expr)
-{
- typedef et::MatrixTransposeOp< matrix<E,AT,BO,L> > ExprT;
- return et::MatrixXpr<ExprT>(ExprT(expr));
-}
-
-/** Matrix transpose operator taking an et::MatrixXpr operand.
- *
- * The parse tree is automatically compressed by hoisting the MatrixXpr's
- * subexpression into the subexpression of the MatrixTransposeOp.
- */
-template<class XprT>
-et::MatrixXpr< et::MatrixTransposeOp<XprT> >
-transpose(MATXPR_ARG_TYPE expr)
-{
- typedef et::MatrixTransposeOp<XprT> ExprT;
- return et::MatrixXpr<ExprT>(ExprT(expr.expression()));
-}
-
-
-/* For notational convenience: */
-
-/** Matrix transpose operator taking a matrix operand. */
-template<typename E, class AT, typename BO, typename L>
-et::MatrixXpr< et::MatrixTransposeOp< matrix<E,AT,BO,L> > >
-T(const matrix<E,AT,BO,L>& expr)
-{
- return transpose(expr);
-}
-
-/** Matrix transpose operator taking an et::MatrixXpr operand.
- *
- * The parse tree is automatically compressed by hoisting the MatrixXpr's
- * subexpression into the subexpression of the MatrixTransposeOp.
- */
-template<class XprT>
-et::MatrixXpr< et::MatrixTransposeOp<XprT> >
-T(MATXPR_ARG_TYPE expr)
-{
- return transpose(expr);
-}
-
-#endif
-
-} // namespace cml
-
-#endif
-
-// -------------------------------------------------------------------------
-// vim:ft=cpp