Example usage for org.apache.commons.math3.analysis BivariateFunction BivariateFunction

Introduction

In this page you can find the example usage for org.apache.commons.math3.analysis BivariateFunction BivariateFunction.

Prototype

BivariateFunction

Source Link

Usage

From source file:au.gov.ga.conn4d.utils.BicubicSplineInterpolatingFunction.java

/**
 * Compute all partial derivatives functions.
 *///from  ww  w  .ja v  a  2  s  .c  o m
private void computePartialDerivatives() {
    final double[][] aX = new double[N][N];
    final double[][] aY = new double[N][N];
    final double[][] aXX = new double[N][N];
    final double[][] aYY = new double[N][N];
    final double[][] aXY = new double[N][N];

    for (int i = 0; i < N; i++) {
        for (int j = 0; j < N; j++) {
            final double c = a[i][j];
            aX[i][j] = i * c;
            aY[i][j] = j * c;
            aXX[i][j] = (i - 1) * aX[i][j];
            aYY[i][j] = (j - 1) * aY[i][j];
            aXY[i][j] = j * aX[i][j];
        }
    }

    partialDerivativeX = new BivariateFunction() {
        public double value(double x, double y) {
            final double x2 = x * x;
            final double[] pX = { 0, 1, x, x2 };

            final double y2 = y * y;
            final double y3 = y2 * y;
            final double[] pY = { 1, y, y2, y3 };

            return apply(pX, pY, aX);
        }
    };
    partialDerivativeY = new BivariateFunction() {
        public double value(double x, double y) {
            final double x2 = x * x;
            final double x3 = x2 * x;
            final double[] pX = { 1, x, x2, x3 };

            final double y2 = y * y;
            final double[] pY = { 0, 1, y, y2 };

            return apply(pX, pY, aY);
        }
    };
    partialDerivativeXX = new BivariateFunction() {
        public double value(double x, double y) {
            final double[] pX = { 0, 0, 1, x };

            final double y2 = y * y;
            final double y3 = y2 * y;
            final double[] pY = { 1, y, y2, y3 };

            return apply(pX, pY, aXX);
        }
    };
    partialDerivativeYY = new BivariateFunction() {
        public double value(double x, double y) {
            final double x2 = x * x;
            final double x3 = x2 * x;
            final double[] pX = { 1, x, x2, x3 };

            final double[] pY = { 0, 0, 1, y };

            return apply(pX, pY, aYY);
        }
    };
    partialDerivativeXY = new BivariateFunction() {
        public double value(double x, double y) {
            final double x2 = x * x;
            final double[] pX = { 0, 1, x, x2 };

            final double y2 = y * y;
            final double[] pY = { 0, 1, y, y2 };

            return apply(pX, pY, aXY);
        }
    };
}

---