net.simplace.client.simulation.lap.util.helper.DataTransformHelper

Methods for interpolating and integrating piecewise linear functions

Functions are given by arrays of x and y values.

The class provides methods for

interpolating a value
calculating the integral of the function
rescales the function to have area of 1

public class DataTransformHelper {
// Public Constructors
public DataTransformHelper();

// Class Methods

public static double[] NormalizeCurve(double[] xs, double[] ys);

Normalizes the y-values of an x-y-curve so that the area under the curve is 1.

xs the x values
ys the y values

returns new y values

public static double[] NormalizeCurve(double[] xs, double[] ys, double area);

Normalizes the y-values of an x-y-curve so that the area under the curve has given value.

xs the x values
ys the y values
area the target area under the new curve

returns new y values

public static double[] RescaleValues(double min, double max, double[] vs);

Rescales an array of values proportionally from new mininimum to new maximum.

min minimum value of the new array
max maximum value of the new array
vs values

returns the rescaled values

public static double Interpolate(double x, double[] xs, double[] ys, boolean
extrapolate);

Linear interpolation of a piecewise linear curve

x position where the value should be interpolated
xs array of x values
ys array of corresponding y values
extrapolate if true then first or last y value is returned if x is out of range, if false 0 is returned

returns the interpolated value

public static double Integral(double[] xs, double[] ys);

Calculates the area under the curve defined by arrays of x and y values

xs the x values defining the curve
ys the y values defining the curve

returns the area

public static double IntegralFromTo(double t1, double t2, double[] xs,
double[] ys);

Calculates the area under the curve defined by arrays of x and y values between the points t1 and t2

t1 lower boundary of integration interval
t2 upper boundary of integration interval
xs the x values defining the curve
ys the y values defining the curve

returns the area

}