Method gaussian

src/org/opensourcephysics/display2d/TestData.java:33–36

A 2D Gaussian distribution function centered at x=0 and y=0 and standard deviation of 1.

(double x, double y, double sigma)

   * A 2D Gaussian distribution function centered at x=0 and y=0 and standard deviation of 1.
   */
  public static double gaussian(double x, double y, double sigma) {
    double rSqr = x*x+y*y;
    return Math.exp(-rSqr/sigma/sigma/2);
  }

  /**
   * Saddle function centered at x=0 and y=0.