Mercurial > hg > svcore
view base/LogRange.cpp @ 441:288f45533041
* Add region model and layer; improve assignment of model types to
feature extraction transforms with duration
author | Chris Cannam |
---|---|
date | Thu, 18 Sep 2008 16:08:14 +0000 |
parents | 2268963dabd1 |
children | 9525c9d7e54d |
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/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */ /* Sonic Visualiser An audio file viewer and annotation editor. Centre for Digital Music, Queen Mary, University of London. This file copyright 2006 Chris Cannam. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. See the file COPYING included with this distribution for more information. */ #include "LogRange.h" #include <algorithm> #include <cmath> void LogRange::mapRange(float &min, float &max, float logthresh) { if (min > max) std::swap(min, max); if (max == min) max = min + 1; if (min >= 0.f) { max = log10f(max); // we know max != 0 if (min == 0.f) min = std::min(logthresh, max); else min = log10f(min); } else if (max <= 0.f) { min = log10f(-min); // we know min != 0 if (max == 0.f) max = std::min(logthresh, min); else max = log10f(-max); std::swap(min, max); } else { // min < 0 and max > 0 max = log10f(std::max(max, -min)); min = std::min(logthresh, max); } if (min == max) min = max - 1; } float LogRange::map(float value, float thresh) { if (value == 0.f) return thresh; return log10f(fabsf(value)); } float LogRange::unmap(float value) { return powf(10.0, value); }