Class PolynomialFitter

java.lang.Object
org.apache.commons.math.optimization.fitting.PolynomialFitter

public class PolynomialFitter extends Object
This class implements a curve fitting specialized for polynomials.

Polynomial fitting is a very simple case of curve fitting. The estimated coefficients are the polynomial coefficients. They are searched by a least square estimator.

Since:
2.0
Version:
$Revision: 1073270 $ $Date: 2011-02-22 10:19:27 +0100 (mar. 22 févr. 2011) $
  • Constructor Details

    • PolynomialFitter

      public PolynomialFitter(int degree, DifferentiableMultivariateVectorialOptimizer optimizer)
      Simple constructor.

      The polynomial fitter built this way are complete polynomials, ie. a n-degree polynomial has n+1 coefficients.

      Parameters:
      degree - maximal degree of the polynomial
      optimizer - optimizer to use for the fitting
  • Method Details

    • addObservedPoint

      public void addObservedPoint(double weight, double x, double y)
      Add an observed weighted (x,y) point to the sample.
      Parameters:
      weight - weight of the observed point in the fit
      x - abscissa of the point
      y - observed value of the point at x, after fitting we should have P(x) as close as possible to this value
    • clearObservations

      public void clearObservations()
      Remove all observations.
      Since:
      2.2
    • fit

      Get the polynomial fitting the weighted (x, y) points.
      Returns:
      polynomial function best fitting the observed points
      Throws:
      OptimizationException - if the algorithm failed to converge