- All Implemented Interfaces:
public class GaussianFittingFunction extends java.lang.Object implements FittingFunctionGaussian function for parameter fitting
Based loosely on fgauss in the book "Numerical Recipies".
We did not bother to implement all optimizations at the benefit of having easier to use parameters. Instead of position, amplitude and width used in the book, we use the traditional Gaussian parameters mean, standard deviation and a linear scaling factor (which is mostly useful when combining multiple distributions) The cost are some additional computations such as a square root and probably a slight loss in precision. This could of course have been handled by an appropriate wrapper instead.
Due to their license, we cannot use their code, but we have to implement the mathematics ourselves. We hope the loss in precision isn't big.
They are also arranged differently: the book uses
amplitude, position, widthwhereas we use
mean, stddev, scaling.
But we're obviously using essentially the same mathematics.
The function also can use a mixture of gaussians, just use an appropriate number of parameters (which obviously needs to be a multiple of 3)
- Erich Schubert
Fields Modifier and Type Field Description
Constructors Constructor Description
All Methods Instance Methods Concrete Methods Modifier and Type Method Description
eval(double x, double params)Compute the mixture of Gaussians at the given position
public static final GaussianFittingFunction STATICStatic instance
public FittingFunctionResult eval(double x, double params)Compute the mixture of Gaussians at the given position
- Specified by:
x- Current coordinate
params- Function parameters parameters
- Array consisting of y value and parameter gradients