30 lines
853 B
C++
30 lines
853 B
C++
// Regression is a class to compute a linear regression
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//
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// call point(x, y) to add a data point
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// call regress() to compute the regression
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// call f(x) to evaluate the linear regression at x
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// call f_inv(y) to evaluate the inverse linear regression at y
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// to restart with new points, call init()
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// regress() can be called after each point()
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//
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// other forms of regression should be added. This one does
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// standard least squares regression
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class Regression {
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float sumxx; // sum of x^2
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float sumyy; // sum of y^2
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float sumxy; // sum of xy
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float sumx; // sum of x
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float sumy; // sum of y
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int n; // number of points
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float a, b; // regression line is a + b*x
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public:
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Regression();
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void init();
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void point(float x, float y);
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void regress();
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float f(float x);
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float f_inv(float y);
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};
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