Histogram.cpp

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// kate: replace-tabs off; indent-width 4; indent-mode normal
// vim: ts=4:sw=4:noexpandtab
/*

Copyright (c) 2010--2012,
François Pomerleau and Stephane Magnenat, ASL, ETHZ, Switzerland
You can contact the authors at <f dot pomerleau at gmail dot com> and
<stephane at magnenat dot net>

All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
    * Redistributions of source code must retain the above copyright
      notice, this list of conditions and the following disclaimer.
    * Redistributions in binary form must reproduce the above copyright
      notice, this list of conditions and the following disclaimer in the
      documentation and/or other materials provided with the distribution.
    * Neither the name of the <organization> nor the
      names of its contributors may be used to endorse or promote products
      derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL ETH-ASL BE LIABLE FOR ANY
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*/

#include "Histogram.h"

#include <iostream>
#include <fstream>
#include <iomanip>
#include <limits>
#include <algorithm>
#include <boost/format.hpp>

namespace PointMatcherSupport
{
        using namespace std;
        
        template<typename T>
        Histogram<T>::Histogram(const size_t binCount, const std::string& name, const std::string& 
                filePrefix, const bool dumpStdErrOnExit):
                binCount(binCount),
                name(name),
                filePrefix(filePrefix),
                dumpStdErrOnExit(dumpStdErrOnExit)
        {
        }
        
        template<typename T>
        Histogram<T>::~Histogram()
        {
                T meanV, varV, medianV, lowQt, highQt, minV, maxV;
                uint64_t maxBinC;
                if (!dumpStdErrOnExit && filePrefix.empty())
                        return;
                        
                const vector<uint64_t> bins(computeStats(meanV, varV, medianV, lowQt, highQt, minV, maxV, maxBinC));
                
                if (!filePrefix.empty())
                {
                        std::cerr << "writing to " << (filePrefix + name) << std::endl;
                        std::ofstream ofs((filePrefix + name).c_str());
                        for (size_t i = 0; i < this->size(); ++i)
                                ofs << ((*this)[i]) << "\n";
                }
                
                if (dumpStdErrOnExit)
                {
                        std::cerr.precision(4);
                        std::cerr.fill(' ');
                        std::cerr.flags(std::ios::left);
                        std::cerr << "Histogram " << name << ":\n";
                        std::cerr << "  count: " << this->size() << ", mean: " << meanV << "\n";
                        if(this->size() > 1)
                        {
                                for (size_t i = 0; i < binCount; ++i)
                                {
                                        const T v(minV + i * (maxV - minV) / T(binCount));
                                        std::cerr << "  " << std::setw(10) << v << " (" << std::setw(6) << bins[i] << ") : ";
                                        //std::cerr << (bins[i] * 60) / maxBinC << " " ;
                                        for (size_t j = 0; j < (bins[i] * 60) / maxBinC; ++j)
                                                std::cerr << "*";
                                        std::cerr << "\n";
                                }
                                std::cerr << std::endl;
                        }
                }
        }
        
        template<typename T>
        vector<uint64_t> Histogram<T>::computeStats(T& meanV, T& varV, T& medianV, T& lowQt, T& highQt, T& minV, T& maxV, uint64_t& maxBinC)
        {
                typedef typename std::vector<T>::iterator Iterator;
                vector<uint64_t> bins(binCount, 0);
                
                //assert(this->size() > 0);
                if(this->size() > 0)
                {
                        // basic stats
                        meanV = 0;
                        minV = std::numeric_limits<T>::max();
                        maxV = std::numeric_limits<T>::min();
                        for (size_t i = 0; i < this->size(); ++i)
                        {
                                const T v((*this)[i]);
                                meanV += v;
                                minV = std::min<T>(minV, v);
                                maxV = std::max<T>(maxV, v);
                        }
                        meanV /= T(this->size());
                        // var and hist
                        std::fill(bins.begin(), bins.end(), uint64_t(0));
                        maxBinC = 0;
                        varV = 0;
                        if (minV == maxV)
                        {
                                medianV = lowQt = highQt = minV;
                                return bins;
                        }
                        for (size_t i = 0; i < this->size(); ++i)
                        {
                                const T v((*this)[i]);
                                varV += (v - meanV)*(v - meanV);
                                const size_t index((v - minV) * (binCount) / ((maxV - minV) * (1+std::numeric_limits<T>::epsilon()*10)));
                                //std::cerr << "adding value " << v << " to index " << index << std::endl;
                                ++bins[index];
                                maxBinC = std::max<uint64_t>(maxBinC, bins[index]);
                        }
                        varV /= T(this->size());
                        // median
                        const Iterator lowQtIt(this->begin() + (this->size() / 4));
                        const Iterator medianIt(this->begin() + (this->size() / 2));
                        const Iterator highQtIt(this->begin() + (3*this->size() / 4));
                        std::nth_element(this->begin(), medianIt, this->end());
                        medianV = *medianIt;
                        std::nth_element(this->begin(), lowQtIt, this->end());
                        lowQt = *lowQtIt;
                        std::nth_element(this->begin(), highQtIt, this->end());
                        highQt = *highQtIt;
                }
                else
                {
                        meanV = std::numeric_limits<T>::quiet_NaN();
                        varV = std::numeric_limits<T>::quiet_NaN();
                        medianV = std::numeric_limits<T>::quiet_NaN();
                        lowQt = std::numeric_limits<T>::quiet_NaN();
                        highQt = std::numeric_limits<T>::quiet_NaN();
                        minV = std::numeric_limits<T>::quiet_NaN();
                        maxV = std::numeric_limits<T>::quiet_NaN();
                        maxBinC = 0;
                }
                return bins;
        }
        
        template<typename T>
        void Histogram<T>::dumpStats(std::ostream& os)
        {
                T meanV, varV, medianV, lowQt, highQt, minV, maxV;
                uint64_t maxBinC;
                const vector<uint64_t> bins(computeStats(meanV, varV, medianV, lowQt, highQt, minV, maxV, maxBinC));
                os << this->size() << ", " << meanV << ", " << varV << ", " << medianV << ", " << lowQt << ", " << highQt << ", " << minV << ", " << maxV << ", " << binCount << ", ";
                
                for (size_t i = 0; i < binCount; ++i)
                        os << bins[i] << ", ";
                os << maxBinC;
        }
        
        template<typename T>
        void Histogram<T>::dumpStatsHeader(std::ostream& os) const
        {
                os << name + "_count, ";
                os << name + "_mean, ";
                os << name + "_var, ";
                os << name + "_median, ";
                os << name + "_low_quartile, ";
                os << name + "_high_quartile, ";
                os << name + "_min_value, ";
                os << name + "_max_value, ";
                os << name + "_bin_count, ";
                for (size_t i = 0; i < binCount; ++i)
                        os << (boost::format("%1%_bin_%2%,") % name % i).str();
                os << name + "_max_elements_per_bin ";
        }
        
        template struct Histogram<unsigned>;
        template struct Histogram<float>;
        template struct Histogram<double>;
} // namespace PointMatcherSupport