[Olena-patches] 699: Add xtd L2 norm for vec.

2006-11-07 Thierry GERAUD &lt;theo(a)tegucigalpa.lrde.epita.fr&gt; * xtd/vec.hh (L2_norm): New. (include): Add cmath header. Index: xtd/vec.hh =================================================================== --- xtd/vec.hh (revision 694) +++ xtd/vec.hh (working copy) @@ -29,6 +29,8 @@ # define XTD_VEC_HH # include <iostream> +# include <cmath> + # include <mlc/contract.hh> # include <xtd/optraits.hh> @@ -317,6 +319,8 @@ } + // lexi_less. + struct lexi_less_t { template <unsigned n, typename T> @@ -331,7 +335,6 @@ } }; - template <unsigned n, typename T> bool lexi_less(const vec<n,T>& lhs, const vec<n,T>& rhs) { @@ -340,6 +343,19 @@ } + // L2_norm. + + template <unsigned n, typename T> + float L2_norm(const vec<n,T>& v) + { + float val = 0.f; + for (unsigned i = 0; i < n; ++i) + val += float(v[i]) * float(v[i]); + return std::sqrt(val); + } + + + template <typename uop, unsigned n, typename T> struct set_trait_< uop, vec<n,T> >