Mercurial > hg > svcore
view base/LogRange.cpp @ 1310:aa1b1fc2d018 mp3-gapless
Stop reporting sync errors only when we really are at eof, i.e. after the input callback has been called again (previously we just tested whether we'd buffered up all the input, which of course we do in one go at the start)
author | Chris Cannam |
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date | Tue, 29 Nov 2016 16:45:29 +0000 |
parents | d4212687520e |
children | b061b9f8fca5 |
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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 "system/System.h" #include <algorithm> #include <iostream> #include <cmath> void LogRange::mapRange(double &min, double &max, double logthresh) { if (min > max) std::swap(min, max); if (max == min) max = min + 1; // cerr << "LogRange::mapRange: min = " << min << ", max = " << max << endl; if (min >= 0.f) { max = log10(max); // we know max != 0 if (min == 0.f) min = std::min(logthresh, max); else min = log10(min); // cerr << "LogRange::mapRange: positive: min = " << min << ", max = " << max << endl; } else if (max <= 0.f) { min = log10(-min); // we know min != 0 if (max == 0.f) max = std::min(logthresh, min); else max = log10(-max); std::swap(min, max); // cerr << "LogRange::mapRange: negative: min = " << min << ", max = " << max << endl; } else { // min < 0 and max > 0 max = log10(std::max(max, -min)); min = std::min(logthresh, max); // cerr << "LogRange::mapRange: spanning: min = " << min << ", max = " << max << endl; } if (min == max) min = max - 1; } double LogRange::map(double value, double thresh) { if (value == 0.f) return thresh; return log10(fabs(value)); } double LogRange::unmap(double value) { return pow(10.0, value); } static double sd(const std::vector<double> &values, int start, int n) { double sum = 0.f, mean = 0.f, variance = 0.f; for (int i = 0; i < n; ++i) { sum += values[start + i]; } mean = sum / n; for (int i = 0; i < n; ++i) { double diff = values[start + i] - mean; variance += diff * diff; } variance = variance / n; return sqrt(variance); } bool LogRange::useLogScale(std::vector<double> values) { // Principle: Partition the data into two sets around the median; // calculate the standard deviation of each set; if the two SDs // are very different, it's likely that a log scale would be good. int n = int(values.size()); if (n < 4) return false; std::sort(values.begin(), values.end()); int mi = n / 2; double sd0 = sd(values, 0, mi); double sd1 = sd(values, mi, n - mi); SVDEBUG << "LogRange::useLogScale: sd0 = " << sd0 << ", sd1 = " << sd1 << endl; if (sd0 == 0 || sd1 == 0) return false; // I wonder what method of determining "one sd much bigger than // the other" would be appropriate here... if (std::max(sd0, sd1) / std::min(sd0, sd1) > 10.) return true; else return false; }