Class GaussianFittingFunction

  • All Implemented Interfaces:

    public class GaussianFittingFunction
    extends java.lang.Object
    implements FittingFunction
    Gaussian 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, width whereas 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
    • Constructor Detail

      • GaussianFittingFunction

        public GaussianFittingFunction()
    • Method Detail

      • eval

        public FittingFunctionResult eval​(double x,
                                          double[] params)
        Compute the mixture of Gaussians at the given position
        Specified by:
        eval in interface FittingFunction
        x - Current coordinate
        params - Function parameters parameters
        Array consisting of y value and parameter gradients