Package io.github.ai4ci.util

Class SplineInterpolator

java.lang.Object

io.github.ai4ci.util.SplineInterpolator

All Implemented Interfaces:

Serializable

public class SplineInterpolator
extends Object
implements Serializable

Performs spline interpolation given a set of control points.

See Also:

• Serialized Form

Method Summary

Modifier and Type	Method	Description
static SplineInterpolator	createMonotoneCubicSpline(double[] x, double[] y)	Creates a monotone cubic spline from a given set of control points.
double	interpolate(double x)	Interpolates the value of Y = f(X) for given X.
double	interpolateDifferential(double x)	Interpolates the value of Y = f(X) for given X.
String	toString()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Method Details

createMonotoneCubicSpline

public static SplineInterpolator createMonotoneCubicSpline(double[] x,
 double[] y)

Creates a monotone cubic spline from a given set of control points. The spline is guaranteed to pass through each control point exactly. Moreover, assuming the control points are monotonic (Y is non-decreasing or non-increasing) then the interpolated values will also be monotonic. This function uses the Fritsch-Carlson method for computing the spline parameters. http://en.wikipedia.org/wiki/Monotone_cubic_interpolation

Parameters:

x - The X component of the control points, strictly increasing.

y - The Y component of the control points

Throws:

IllegalArgumentException - if the X or Y arrays are null, have different lengths or have fewer than 2 values.

interpolateDifferential

public double interpolateDifferential(double x)

Interpolates the value of Y = f(X) for given X. Clamps X to the domain of the spline.

Parameters:

x - The X value.

Returns:

The interpolated Y = f(X) value.

interpolate

public double interpolate(double x)

Interpolates the value of Y = f(X) for given X. Clamps X to the domain of the spline.

Parameters:

x - The X value.

Returns:

The interpolated Y = f(X) value.

toString

public String toString()

Overrides:

toString in class Object