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Ublas : |
From: Karl Meerbergen (Karl.Meerbergen_at_[hidden])
Date: 2007-08-24 07:22:54
Hi,
What is the advantage of boost::rational numbers compared to floating
numbers?
Thanks,
Karl
Leopoldo Peralta wrote:
>Additionally to complex types, should boost::rational numbers (which is a
>boost type) be included?
>
>Regards
>
>Leopoldo Peralta
>
>-----Mensaje original-----
>De: ublas-bounces_at_[hidden] [mailto:ublas-bounces_at_[hidden]] En
>nombre de Neal Becker
>Enviado el: Thursday, August 23, 2007 1:35 PM
>Para: ublas_at_[hidden]
>Asunto: [ublas] [patch] improve type deduction
>
>This patch does 2 things:
>1) enable mixed int/complex arith
>2) use boost typeof for return type deduction
>
>diff -r 1be5d7eb10aa boost/numeric/ublas/traits.hpp
>--- a/boost/numeric/ublas/traits.hpp Mon Aug 20 09:58:57 2007 -0400
>+++ b/boost/numeric/ublas/traits.hpp Thu Aug 23 14:34:22 2007 -0400
>@@ -27,8 +27,44 @@
>
> #include <boost/type_traits.hpp>
> #include <complex>
>+#include <boost/typeof/typeof.hpp>
>
> namespace boost { namespace numeric { namespace ublas {
>+
>+typedef std::complex<double> complex_t;
>+
>+inline complex_t operator+ (int in1, complex_t in2) {
>+ return double(in1) + in2;
>+}
>+
>+inline complex_t operator+ (complex_t in1, int in2) {
>+ return in1 + double(in2);
>+}
>+
>+inline complex_t operator- (int in1, complex_t in2) {
>+ return double(in1) - in2;
>+}
>+
>+inline complex_t operator- (complex_t in1, int in2) {
>+ return in1 - double(in2);
>+}
>+
>+inline complex_t operator* (int in1, complex_t in2) {
>+ return double(in1) * in2;
>+}
>+
>+inline complex_t operator* (complex_t in1, int in2) {
>+ return in1 * double(in2);
>+}
>+
>+inline complex_t operator/ (int in1, complex_t in2) {
>+ return double(in1) / in2;
>+}
>+
>+inline complex_t operator/ (complex_t in1, int in2) {
>+ return in1 / double(in2);
>+}
>+
>
> // Use Joel de Guzman's return type deduction
> // uBLAS assumes a common return type for all binary arithmetic
>operators
>@@ -37,17 +73,19 @@ namespace boost { namespace numeric { na
> typedef type_deduction_detail::base_result_of<X, Y> base_type;
> static typename base_type::x_type x;
> static typename base_type::y_type y;
>- static const std::size_t size = sizeof (
>- type_deduction_detail::test<
>- typename base_type::x_type
>- , typename base_type::y_type
>- >(x + y) // Use x+y to stand of all the arithmetic
>actions
>- );
>-
>- static const std::size_t index = (size / sizeof (char)) - 1;
>- typedef typename mpl::at_c<
>- typename base_type::types, index>::type id;
>- typedef typename id::type promote_type;
>+// static const std::size_t size = sizeof (
>+// type_deduction_detail::test<
>+// typename base_type::x_type
>+// , typename base_type::y_type
>+// >(x + y) // Use x+y to stand of all the arithmetic
>actions
>+// );
>+
>+// static const std::size_t index = (size / sizeof (char)) - 1;
>+// typedef typename mpl::at_c<
>+// typename base_type::types, index>::type id;
>+ // typedef typename id::type promote_type;
>+ // typedef typeof (X() + Y()) promote_type;
>+ typedef BOOST_TYPEOF (X() + Y()) promote_type;
> };
>
>
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