Class PeriodicFunction

java.lang.Object

org.ojalgo.function.series.PeriodicFunction

All Implemented Interfaces:

DoubleUnaryOperator, Function<Double,Double>, UnaryOperator<Double>, BasicFunction, PrimitiveFunction.Unary, UnaryFunction<Double>

public final class PeriodicFunction
extends Object
implements PrimitiveFunction.Unary

A periodic function is a function that repeats its values in regular intervals or periods. The most important examples are the trigonometric functions, which repeat over intervals of length 2π radians.

This class allows you to create a periodic function from any other function. The base function only needs to be defined over the interval specified in this class, The resulting function will repeat the base function in regular periods. The default period is 2π, but it's possible to specify any other period. The default origin is zero, but it's possible to specify any other origin.

Nested Class Summary

Nested classes/interfaces inherited from interface BasicFunction

BasicFunction.Differentiable<N,F>, BasicFunction.Integratable<N,F>, BasicFunction.PlainUnary<T,R>

Field Summary

Fields

Modifier and Type	Field	Description
private final double	myOrigin
private final double	myPeriod
private final DoubleUnaryOperator	myShape
static final PeriodicFunction	SAWTOOTH	https://en.wikipedia.org/wiki/Sawtooth_wave
static final PeriodicFunction	SINE	https://en.wikipedia.org/wiki/Sine_wave
static final PeriodicFunction	SQUARE	https://en.wikipedia.org/wiki/Square_wave
static final PeriodicFunction	TRIANGLE	https://en.wikipedia.org/wiki/Triangle_wave

Constructor Summary

Constructors

Constructor	Description
PeriodicFunction(double origin, DoubleUnaryOperator shape, double period)

Method Summary

Modifier and Type	Method	Description
PrimitiveFunction.SampleDomain	getSampleDomain(int nbSamples)
double	invoke(double arg)
static PeriodicFunction	of(double origin, DoubleUnaryOperator shape)
static PeriodicFunction	of(DoubleUnaryOperator shape)	Origin at zero, and period 2π [0, 2π).
static DoubleUnaryOperator	of(DoubleUnaryOperator shape, double period)
static PeriodicFunction	ofCentered(DoubleUnaryOperator shape)	Origin at -π, and period 2π [-π, π).
PeriodicFunction	withInterval(double origin, double period)	interval = [origin, origin+period)
PeriodicFunction	withOrigin(double origin)	interval = [origin, origin+period)
PeriodicFunction	withPeriod(double period)	interval = [origin, origin+period)
PeriodicFunction	withShape(DoubleUnaryOperator shape)	The shape is the function that is repeated in regular intervals.

Methods inherited from class Object

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

Methods inherited from interface DoubleUnaryOperator

andThen, compose

Methods inherited from interface Function

andThen, compose

Methods inherited from interface PrimitiveFunction.Unary

invoke

Methods inherited from interface UnaryFunction

andThen, apply, applyAsDouble, compose, invoke, invoke, invoke, invoke, invoke

Field Details

SAWTOOTH

public static final PeriodicFunction SAWTOOTH

https://en.wikipedia.org/wiki/Sawtooth_wave

Domain: (-∞, ∞) by repeating/shifting the definition interval [0, 2π).
Range: [-1, 1].

SINE

public static final PeriodicFunction SINE

https://en.wikipedia.org/wiki/Sine_wave

Domain: (-∞, ∞) by repeating/shifting the definition interval [0, 2π).
Range: [-1, 1].

SQUARE

public static final PeriodicFunction SQUARE

https://en.wikipedia.org/wiki/Square_wave

Domain: (-∞, ∞) by repeating/shifting the definition interval [0, 2π).
Range: [-1, 1].

TRIANGLE

public static final PeriodicFunction TRIANGLE

https://en.wikipedia.org/wiki/Triangle_wave

Domain: (-∞, ∞) by repeating/shifting the definition interval [0, 2π).
Range: [-1, 1].

myOrigin

private final double myOrigin

myPeriod

private final double myPeriod

myShape

private final DoubleUnaryOperator myShape

Constructor Details

PeriodicFunction

PeriodicFunction(double origin,
 DoubleUnaryOperator shape,
 double period)

Method Details

of

public static PeriodicFunction of(double origin,
 DoubleUnaryOperator shape)

of

public static PeriodicFunction of(DoubleUnaryOperator shape)

Origin at zero, and period 2π [0, 2π).

of

public static DoubleUnaryOperator of(DoubleUnaryOperator shape,
 double period)

ofCentered

public static PeriodicFunction ofCentered(DoubleUnaryOperator shape)

Origin at -π, and period 2π [-π, π).

getSampleDomain

public PrimitiveFunction.SampleDomain getSampleDomain(int nbSamples)

invoke

public double invoke(double arg)

Specified by:

invoke in interface UnaryFunction<Double>

withInterval

public PeriodicFunction withInterval(double origin,
 double period)

interval = [origin, origin+period)

withOrigin

public PeriodicFunction withOrigin(double origin)

interval = [origin, origin+period)

withPeriod

public PeriodicFunction withPeriod(double period)

interval = [origin, origin+period)

withShape

public PeriodicFunction withShape(DoubleUnaryOperator shape)

The shape is the function that is repeated in regular intervals.