[Olena-patches] oln 10.218: Optimize Hermite polynomials computation in Shapelets transform.

Index: olena/ChangeLog from Damien Thivolle &lt;damien(a)lrde.epita.fr&gt; * oln/transforms/shapelets.hh: Optimize Hermite polynomials computation. Index: olena/oln/transforms/shapelets.hh --- olena/oln/transforms/shapelets.hh Sat, 26 Jun 2004 23:19:24 +0200 thivol_d (oln/r/10_shapelets. 1.4 600) +++ olena/oln/transforms/shapelets.hh Sat, 11 Sep 2004 01:29:25 +0200 thivol_d (oln/r/10_shapelets. 1.4 600) @@ -18,12 +18,23 @@ { T operator()(unsigned n, T x) { + T a; + T b; + T c; if (n == 0) - return 1; + return 1.; if (n == 1) return 2. * x; - return 2. * x * (*this)(n - 1, x) - 2. * T(n - 1) * (*this)(n - 2, x); + a = 1.; + b = 2. * x; + for (unsigned i = 2; i <= n; i++) + { + c = b; + b = 2. * x * b - 2. * T(i - 1) * a; + a = c; + } + return b; } }; Ben ca va plus vite. -- Damien Thivolle damien.thivolle(a)lrde.epita.fr