Exponential Fit with apache commons math
apache-commons-math, java, math
Solution
If you are trying to estimate this I suggest you take the log of y which will give you a graph
y' = log(y) = A - B * x;
From this you can calculate the slope and the intercept.
slope = sum((x - mean(x)) * (y' - mean(y')) / sum((x - mean(x))^2) // -B
intercept = mean(y' - x * slope) // A
Problem
I'm trying to do an exponential fit on various points (x,y) with the formula A*EXP(-BX), trying to find A and B that best suit my points. ``` double[] xx = curveFitter.fit(new ParametricUnivariateFunction() { public double value(double v, double... doubles) { return doubles[0] * Math.exp(-1 * doubles[1] * v); } public double[] gradient(double v, double... doubles) { return new double[]{v, 1}; } }, new double[]{0, 0}); ``` I get some numbers but they don't fit my points in any way, Can't seem to find any documentation on the above. Using commons-math3-3.0