X-Git-Url: https://git.dogcows.com/gitweb?a=blobdiff_plain;ds=sidebyside;f=src%2Fcml%2Fmatvec%2Fmatvec_mul.h;fp=src%2Fcml%2Fmatvec%2Fmatvec_mul.h;h=5f5ea92e0d4c18ea7c1bf6cac25ea8c6783912cb;hb=6b0a0d0efafe34d48ab344fca3b479553bd4e62c;hp=0000000000000000000000000000000000000000;hpb=85783316365181491a3e3c0c63659972477cebba;p=chaz%2Fyoink

diff --git a/src/cml/matvec/matvec_mul.h b/src/cml/matvec/matvec_mul.h
new file mode 100644
index 0000000..5f5ea92
--- /dev/null
+++ b/src/cml/matvec/matvec_mul.h
@@ -0,0 +1,285 @@
+/* -*- 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 Multiply a matrix and a vector.
+ *
+ * @todo Implement smarter temporary generation.
+ *
+ * @todo Does it make sense to put mat-vec multiplication as a node into the
+ * expression tree?
+ *
+ * @internal This does not need to return an expression type, since the
+ * temporary generation for the matrix result is handled automatically by the
+ * compiler.  i.e. when used in an expression, the result is automatically
+ * included in the expression tree as a temporary by the compiler.
+ */
+
+#ifndef	matvec_mul_h
+#define	matvec_mul_h
+
+#include <cml/core/cml_meta.h>
+#include <cml/vector/vector_expr.h>
+#include <cml/matrix/matrix_expr.h>
+#include <cml/matvec/matvec_promotions.h>
+
+/* This is used below to create a more meaningful compile-time error when
+ * mat-vec mul is not provided with the right arguments:
+ */
+struct mvmul_expects_one_matrix_and_one_vector_arg_error;
+struct mvmul_expects_one_vector_and_one_matrix_arg_error;
+
+namespace cml {
+namespace detail {
+
+/* For choosing the proper multiplication order: */
+typedef true_type mul_Ax;
+typedef false_type mul_xA;
+
+/** Compute y = A*x. */
+template<typename LeftT, typename RightT> inline
+typename et::MatVecPromote<
+    typename et::ExprTraits<LeftT>::result_type,
+    typename et::ExprTraits<RightT>::result_type
+>::temporary_type
+mul(const LeftT& A, const RightT& x, mul_Ax)
+{
+    /* Shorthand: */
+    typedef et::ExprTraits<LeftT> left_traits;
+    typedef et::ExprTraits<RightT> right_traits;
+    typedef typename left_traits::result_tag left_result;
+    typedef typename right_traits::result_tag right_result;
+
+    /* mul()[A*x] requires a matrix and a vector expression: */
+    CML_STATIC_REQUIRE_M(
+        (same_type<left_result, et::matrix_result_tag>::is_true
+         && same_type<right_result, et::vector_result_tag>::is_true),
+        mvmul_expects_one_matrix_and_one_vector_arg_error);
+    /* Note: parens are required here so that the preprocessor ignores the
+     * commas.
+     */
+
+    /* Get result type: */
+    typedef typename et::MatVecPromote<
+        typename left_traits::result_type,
+        typename right_traits::result_type
+    >::temporary_type result_type;
+
+    /* Record size type: */
+    typedef typename result_type::size_tag size_tag;
+
+    /* Check the size: */
+    size_t N = et::CheckedSize(A, x, size_tag());
+
+    /* Initialize the new vector: */
+    result_type y; cml::et::detail::Resize(y, N);
+
+    /* Compute y = A*x: */
+    typedef typename result_type::value_type sum_type;
+    for(size_t i = 0; i < N; ++i) {
+        /* XXX This should be unrolled. */
+        sum_type sum(A(i,0)*x[0]);
+        for(size_t k = 1; k < x.size(); ++k) {
+            sum += (A(i,k)*x[k]);
+        }
+        y[i] = sum;
+    }
+
+    return y;
+}
+
+/** Compute y = x*A. */
+template<typename LeftT, typename RightT> inline
+typename et::MatVecPromote<
+    typename et::ExprTraits<LeftT>::result_type,
+    typename et::ExprTraits<RightT>::result_type
+>::temporary_type
+mul(const LeftT& x, const RightT& A, mul_xA)
+{
+    /* Shorthand: */
+    typedef et::ExprTraits<LeftT> left_traits;
+    typedef et::ExprTraits<RightT> right_traits;
+    typedef typename left_traits::result_tag left_result;
+    typedef typename right_traits::result_tag right_result;
+
+    /* mul()[x*A] requires a vector and a matrix expression: */
+    CML_STATIC_REQUIRE_M(
+        (same_type<left_result, et::vector_result_tag>::is_true
+         && same_type<right_result, et::matrix_result_tag>::is_true),
+        mvmul_expects_one_vector_and_one_matrix_arg_error);
+    /* Note: parens are required here so that the preprocessor ignores the
+     * commas.
+     */
+
+    /* Get result type: */
+    typedef typename et::MatVecPromote<
+        typename left_traits::result_type,
+        typename right_traits::result_type
+    >::temporary_type result_type;
+
+    /* Record size type: */
+    typedef typename result_type::size_tag size_tag;
+
+    /* Check the size: */
+    size_t N = et::CheckedSize(x, A, size_tag());
+
+    /* Initialize the new vector: */
+    result_type y; cml::et::detail::Resize(y, N);
+
+    /* Compute y = x*A: */
+    typedef typename result_type::value_type sum_type;
+    for(size_t i = 0; i < N; ++i) {
+        /* XXX This should be unrolled. */
+        sum_type sum(x[0]*A(0,i));
+        for(size_t k = 1; k < x.size(); ++k) {
+            sum += (x[k]*A(k,i));
+        }
+        y[i] = sum;
+    }
+
+    return y;
+}
+
+} // namespace detail
+
+
+/** operator*() for a matrix and a vector. */
+template<typename E1, class AT1, typename BO, class L,
+         typename E2, class AT2>
+inline typename et::MatVecPromote<
+    matrix<E1,AT1,BO,L>, vector<E2,AT2>
+>::temporary_type
+operator*(const matrix<E1,AT1,BO,L>& left,
+          const vector<E2,AT2>& right)
+{
+    return detail::mul(left,right,detail::mul_Ax());
+}
+
+/** operator*() for a matrix and a VectorXpr. */
+template<typename E, class AT, class L, typename BO, typename XprT>
+inline typename et::MatVecPromote<
+    matrix<E,AT,BO,L>, typename XprT::result_type
+>::temporary_type
+operator*(const matrix<E,AT,BO,L>& left,
+          const et::VectorXpr<XprT>& right)
+{
+    /* Generate a temporary, and compute the right-hand expression: */
+    typename et::VectorXpr<XprT>::temporary_type right_tmp;
+    cml::et::detail::Resize(right_tmp,right.size());
+    right_tmp = right;
+
+    return detail::mul(left,right_tmp,detail::mul_Ax());
+}
+
+/** operator*() for a MatrixXpr and a vector. */
+template<typename XprT, typename E, class AT>
+inline typename et::MatVecPromote<
+    typename XprT::result_type, vector<E,AT>
+>::temporary_type
+operator*(const et::MatrixXpr<XprT>& left,
+          const vector<E,AT>& right)
+{
+    /* Generate a temporary, and compute the left-hand expression: */
+    typename et::MatrixXpr<XprT>::temporary_type left_tmp;
+    cml::et::detail::Resize(left_tmp,left.rows(),left.cols());
+    left_tmp = left;
+
+    return detail::mul(left_tmp,right,detail::mul_Ax());
+}
+
+/** operator*() for a MatrixXpr and a VectorXpr. */
+template<typename XprT1, typename XprT2>
+inline typename et::MatVecPromote<
+    typename XprT1::result_type, typename XprT2::result_type
+>::temporary_type
+operator*(const et::MatrixXpr<XprT1>& left,
+          const et::VectorXpr<XprT2>& right)
+{
+    /* Generate a temporary, and compute the left-hand expression: */
+    typename et::MatrixXpr<XprT1>::temporary_type left_tmp;
+    cml::et::detail::Resize(left_tmp,left.rows(),left.cols());
+    left_tmp = left;
+
+    /* Generate a temporary, and compute the right-hand expression: */
+    typename et::VectorXpr<XprT2>::temporary_type right_tmp;
+    cml::et::detail::Resize(right_tmp,right.size());
+    right_tmp = right;
+
+    return detail::mul(left_tmp,right_tmp,detail::mul_Ax());
+}
+
+/** operator*() for a vector and a matrix. */
+template<typename E1, class AT1, typename E2, class AT2, typename BO, class L>
+inline typename et::MatVecPromote<
+    vector<E1,AT1>, matrix<E2,AT2,BO,L>
+>::temporary_type
+operator*(const vector<E1,AT1>& left,
+          const matrix<E2,AT2,BO,L>& right)
+{
+    return detail::mul(left,right,detail::mul_xA());
+}
+
+/** operator*() for a vector and a MatrixXpr. */
+template<typename XprT, typename E, class AT>
+inline typename et::MatVecPromote<
+    typename XprT::result_type, vector<E,AT>
+>::temporary_type
+operator*(const vector<E,AT>& left,
+          const et::MatrixXpr<XprT>& right)
+{
+    /* Generate a temporary, and compute the right-hand expression: */
+    typename et::MatrixXpr<XprT>::temporary_type right_tmp;
+    cml::et::detail::Resize(right_tmp,right.rows(),right.cols());
+    right_tmp = right;
+
+    return detail::mul(left,right_tmp,detail::mul_xA());
+}
+
+/** operator*() for a VectorXpr and a matrix. */
+template<typename XprT, typename E, class AT, typename BO, class L>
+inline typename et::MatVecPromote<
+    typename XprT::result_type, matrix<E,AT,BO,L>
+>::temporary_type
+operator*(const et::VectorXpr<XprT>& left,
+          const matrix<E,AT,BO,L>& right)
+{
+    /* Generate a temporary, and compute the left-hand expression: */
+    typename et::VectorXpr<XprT>::temporary_type left_tmp;
+    cml::et::detail::Resize(left_tmp,left.size());
+    left_tmp = left;
+
+    return detail::mul(left_tmp,right,detail::mul_xA());
+}
+
+/** operator*() for a VectorXpr and a MatrixXpr. */
+template<typename XprT1, typename XprT2>
+inline typename et::MatVecPromote<
+    typename XprT1::result_type, typename XprT2::result_type
+>::temporary_type
+operator*(const et::VectorXpr<XprT1>& left,
+          const et::MatrixXpr<XprT2>& right)
+{
+    /* Generate a temporary, and compute the left-hand expression: */
+    typename et::VectorXpr<XprT1>::temporary_type left_tmp;
+    cml::et::detail::Resize(left_tmp,left.size());
+    left_tmp = left;
+
+    /* Generate a temporary, and compute the right-hand expression: */
+    typename et::MatrixXpr<XprT2>::temporary_type right_tmp;
+    cml::et::detail::Resize(right_tmp,right.rows(),right.cols());
+    right_tmp = right;
+
+    return detail::mul(left_tmp,right_tmp,detail::mul_xA());
+}
+
+} // namespace cml
+
+#endif
+
+// -------------------------------------------------------------------------
+// vim:ft=cpp