37 lines
797 B
C++
37 lines
797 B
C++
#include <vector>
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#include "LineFit.h"
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bool LineFit(const std::vector<float> x, const std::vector<float> y, int size, double &k, double &b)
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{
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if (size < 2)
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{
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k = 0;
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b = 0;
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return false;
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}
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double x_mean = 0;
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double y_mean = 0;
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for (int i = 0; i < size; i++)
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{
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x_mean += x[i];
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y_mean += y[i];
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}
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x_mean /= size;
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y_mean /= size;
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double Dxx = 0, Dxy = 0, Dyy = 0;
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for (int i = 0; i < size; i++)
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{
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Dxx += (x[i] - x_mean) * (x[i] - x_mean);
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Dxy += (x[i] - x_mean) * (y[i] - y_mean);
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Dyy += (y[i] - y_mean) * (y[i] - y_mean);
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}
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double lambda = ((Dxx + Dyy) - sqrt((Dxx - Dyy) * (Dxx - Dyy) + 4 * Dxy * Dxy)) / 2.0;
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double den = sqrt(Dxy * Dxy + (lambda - Dxx) * (lambda - Dxx));
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k = Dxy / (Dxx - lambda);
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b = (Dxy * x_mean) / (lambda - Dxx) + y_mean;
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return true;
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}
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