org.apache.commons.math3.analysis.function

Class StepFunction

java.lang.Object

org.apache.commons.math3.analysis.function.StepFunction

All Implemented Interfaces:

UnivariateFunction

public class StepFunction
extends java.lang.Object
implements UnivariateFunction

Step function.

Since:

3.0

Field Summary

Fields

Modifier and Type	Field and Description
private double[]	abscissa Abscissae.
private double[]	ordinate Ordinates.

Constructor Summary

Constructors

Constructor and Description
StepFunction(double[] x, double[] y) Builds a step function from a list of arguments and the corresponding values.

Method Summary

Methods

Modifier and Type	Method and Description
double	value(double x) Compute the value of the function.

Methods inherited from class java.lang.Object

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

Field Detail

abscissa

private final double[] abscissa

Abscissae.

ordinate

private final double[] ordinate

Ordinates.

Constructor Detail

StepFunction

public StepFunction(double[] x,
            double[] y)
             throws NullArgumentException,
                    NoDataException,
                    DimensionMismatchException,
                    NonMonotonicSequenceException

Builds a step function from a list of arguments and the corresponding values. Specifically, returns the function h(x) defined by

 h(x) = y[0] for all x < x[1]
        y[1] for x[1] <= x < x[2]
        ...
        y[y.length - 1] for x >= x[x.length - 1]
 

The value of x[0] is ignored, but it must be strictly less than x[1].

Parameters:

x - Domain values where the function changes value.

y - Values of the function.

Throws:

NonMonotonicSequenceException - if the x array is not sorted in strictly increasing order.

NullArgumentException - if x or y are null.

NoDataException - if x or y are zero-length.

DimensionMismatchException - if x and y do not have the same length.

Method Detail

value

public double value(double x)

Compute the value of the function.

Specified by:

value in interface UnivariateFunction

Parameters:

x - Point at which the function value should be computed.

Returns:

the value of the function.