[Olena-patches] 3145: Fix level::stretch.

* mln/level/stretch.hh: Use double variables instead of float because of precision issues. See ticket #179. --- milena/ChangeLog | 7 +++++++ milena/mln/level/stretch.hh | 16 ++++++++++------ 2 files changed, 17 insertions(+), 6 deletions(-) diff --git a/milena/ChangeLog b/milena/ChangeLog index 6364251..d08a017 100644 --- a/milena/ChangeLog +++ b/milena/ChangeLog @@ -1,5 +1,12 @@ 2009-01-09 Guillaume Lazzara &lt;z(a)lrde.epita.fr&gt; + Fix level::stretch. + + * mln/level/stretch.hh: Use double variables instead of float because + of precision issues. See ticket #179. + +2009-01-09 Guillaume Lazzara &lt;z(a)lrde.epita.fr&gt; + Add from_double_to_value dispatch in from_to. * mln/convert/from_to.hxx: add more forward declarations. diff --git a/milena/mln/level/stretch.hh b/milena/mln/level/stretch.hh index e91dbe7..80190b4 100644 --- a/milena/mln/level/stretch.hh +++ b/milena/mln/level/stretch.hh @@ -1,5 +1,5 @@ -// Copyright (C) 2007, 2008 EPITA Research and Development Laboratory -// (LRDE) +// Copyright (C) 2007, 2008, 2009 EPITA Research and Development +// Laboratory (LRDE) // // This file is part of the Olena Library. This library is free // software; you can redistribute it and/or modify it under the terms @@ -44,6 +44,8 @@ # include <mln/level/transform.hh> +# include <mln/value/internal/encoding.hh> +# include <iomanip> namespace mln { @@ -84,21 +86,23 @@ namespace mln estim::min_max(input, min_, max_); if (max_ != min_) { - float + //FIXME: we would like to use float instead of double but we + //can't for precision reasons. See ticket #179. + double min = float(min_), max = float(max_), epsilon = mln_epsilon(float), - m = 0.0f - 0.5f + epsilon, M = mln_max(V) + 0.5f - epsilon, + m = 0.0f - 0.5f + epsilon, a = (M - m) / (max - min), b = (m * max - M * min) / (max - min); - fun::v2v::linear<float, float, V> f(a, b); + fun::v2v::linear<double, double, V> f(a, b); output = level::transform(input, f); } else { initialize(output, input); - // trace::warning("output has no significative data!"); + trace::warning("output has no significative data!"); } trace::exiting("level::impl::stretch"); -- 1.5.6.5