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60 lines
1.4 KiB
60 lines
1.4 KiB
//
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// analyse.hpp
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// AwesomeAttract0r
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//
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// Created by Joshua Moerman on 3/25/12.
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// Copyright (c) 2012 Vadovas. All rights reserved.
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//
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#ifndef AwesomeAttract0r_analyse_hpp
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#define AwesomeAttract0r_analyse_hpp
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#include <cmath>
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inline double distance_squared(double * p1, double * p2, size_t dimension){
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double s = 0;
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for(unsigned int i = 0; i < dimension; ++i){
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s += (p1[i] - p2[i]) * (p1[i] - p2[i]);
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}
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return s;
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}
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struct fractal_dimension_settings{
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double doubling;
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double size;
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size_t chunk_size;
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fractal_dimension_settings()
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: doubling(2.4)
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, size(0.035)
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, chunk_size(200)
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{}
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};
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template <typename Iterator>
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double fractal_dimension(Iterator begin, Iterator end, size_t const dimension, const fractal_dimension_settings settings = fractal_dimension_settings() ) {
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const double size = settings.size;
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const double totalSize = std::sqrt(dimension);
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const double r1 = size * totalSize * size * totalSize;
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const double r2 = r1 * settings.doubling * settings.doubling;
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unsigned int counts[2] = {};
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while(begin != end){
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auto x0 = *begin++;
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for(unsigned int i = 0; i < settings.chunk_size && begin != end; ++i){
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auto x = *begin++;
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auto d = distance_squared(x, x0, dimension);
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if( d <= r1 )
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++counts[0];
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if( d <= r2 )
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++counts[1];
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}
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}
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return std::log((double) counts[1] / (double) counts[0]) / std::log(settings.doubling);
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}
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#endif
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