org.apache.commons.math.analysis
Class ComposableFunction

java.lang.Object
  org.apache.commons.math.analysis.ComposableFunction

All Implemented Interfaces:

UnivariateRealFunction

public abstract class ComposableFunction
extends Object
implements UnivariateRealFunction

Base class for UnivariateRealFunction that can be composed with other functions.

Since:

2.1

Version:

$Revision: 1070725 $ $Date: 2011-02-15 02:31:12 +0100 (mar. 15 févr. 2011) $

Field Summary

static ComposableFunction	ABS The FastMath.abs method wrapped as a ComposableFunction.
static ComposableFunction	ACOS The FastMath.abs method wrapped as a ComposableFunction.
static ComposableFunction	ASIN The FastMath.asin method wrapped as a ComposableFunction.
static ComposableFunction	ATAN The FastMath.atan method wrapped as a ComposableFunction.
static ComposableFunction	CBRT The FastMath.cbrt method wrapped as a ComposableFunction.
static ComposableFunction	CEIL The FastMath.ceil method wrapped as a ComposableFunction.
static ComposableFunction	COS The FastMath.cos method wrapped as a ComposableFunction.
static ComposableFunction	COSH The FastMath.cosh method wrapped as a ComposableFunction.
static ComposableFunction	EXP The FastMath.exp method wrapped as a ComposableFunction.
static ComposableFunction	EXPM1 The FastMath.expm1 method wrapped as a ComposableFunction.
static ComposableFunction	FLOOR The FastMath.floor method wrapped as a ComposableFunction.
static ComposableFunction	IDENTITY The identity function.
static ComposableFunction	INVERT The invert operator wrapped as a ComposableFunction.
static ComposableFunction	LOG The FastMath.log method wrapped as a ComposableFunction.
static ComposableFunction	LOG10 The FastMath.log10 method wrapped as a ComposableFunction.
static ComposableFunction	LOG1P The FastMath.log1p method wrapped as a ComposableFunction.
static ComposableFunction	NEGATE The - operator wrapped as a ComposableFunction.
static ComposableFunction	ONE The constant function always returning 1.
static ComposableFunction	RINT The FastMath.rint method wrapped as a ComposableFunction.
static ComposableFunction	SIGNUM The FastMath.signum method wrapped as a ComposableFunction.
static ComposableFunction	SIN The FastMath.sin method wrapped as a ComposableFunction.
static ComposableFunction	SINH The FastMath.sinh method wrapped as a ComposableFunction.
static ComposableFunction	SQRT The FastMath.sqrt method wrapped as a ComposableFunction.
static ComposableFunction	TAN The FastMath.tan method wrapped as a ComposableFunction.
static ComposableFunction	TANH The FastMath.tanh method wrapped as a ComposableFunction.
static ComposableFunction	ULP The FastMath.ulp method wrapped as a ComposableFunction.
static ComposableFunction	ZERO The constant function always returning 0.

Constructor Summary

ComposableFunction()

Method Summary

ComposableFunction	add(double a) Return a function adding a constant term to the instance.
ComposableFunction	add(UnivariateRealFunction f) Return a function adding the instance and another function.
MultivariateRealFunction	asCollector() Generates a function that iteratively apply instance function on all elements of an array.
MultivariateRealFunction	asCollector(BivariateRealFunction combiner) Generates a function that iteratively apply instance function on all elements of an array.
MultivariateRealFunction	asCollector(BivariateRealFunction combiner, double initialValue) Generates a function that iteratively apply instance function on all elements of an array.
MultivariateRealFunction	asCollector(double initialValue) Generates a function that iteratively apply instance function on all elements of an array.
ComposableFunction	combine(UnivariateRealFunction f, BivariateRealFunction combiner) Return a function combining the instance and another function.
ComposableFunction	divide(UnivariateRealFunction f) Return a function dividing the instance by another function.
ComposableFunction	multiply(double scaleFactor) Return a function scaling the instance by a constant factor.
ComposableFunction	multiply(UnivariateRealFunction f) Return a function multiplying the instance and another function.
ComposableFunction	of(UnivariateRealFunction f) Precompose the instance with another function.
ComposableFunction	postCompose(UnivariateRealFunction f) Postcompose the instance with another function.
ComposableFunction	subtract(UnivariateRealFunction f) Return a function subtracting another function from the instance.
abstract double	value(double x) Compute the value for the function.

Methods inherited from class java.lang.Object

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

Field Detail

ZERO

public static final ComposableFunction ZERO

The constant function always returning 0.

ONE

public static final ComposableFunction ONE

The constant function always returning 1.

IDENTITY

public static final ComposableFunction IDENTITY

The identity function.

ABS

public static final ComposableFunction ABS

The FastMath.abs method wrapped as a ComposableFunction.

NEGATE

public static final ComposableFunction NEGATE

The - operator wrapped as a ComposableFunction.

INVERT

public static final ComposableFunction INVERT

The invert operator wrapped as a ComposableFunction.

SIN

public static final ComposableFunction SIN

The FastMath.sin method wrapped as a ComposableFunction.

SQRT

public static final ComposableFunction SQRT

The FastMath.sqrt method wrapped as a ComposableFunction.

SINH

public static final ComposableFunction SINH

The FastMath.sinh method wrapped as a ComposableFunction.

EXP

public static final ComposableFunction EXP

The FastMath.exp method wrapped as a ComposableFunction.

EXPM1

public static final ComposableFunction EXPM1

The FastMath.expm1 method wrapped as a ComposableFunction.

ASIN

public static final ComposableFunction ASIN

The FastMath.asin method wrapped as a ComposableFunction.

ATAN

public static final ComposableFunction ATAN

The FastMath.atan method wrapped as a ComposableFunction.

TAN

public static final ComposableFunction TAN

The FastMath.tan method wrapped as a ComposableFunction.

TANH

public static final ComposableFunction TANH

The FastMath.tanh method wrapped as a ComposableFunction.

CBRT

public static final ComposableFunction CBRT

The FastMath.cbrt method wrapped as a ComposableFunction.

CEIL

public static final ComposableFunction CEIL

The FastMath.ceil method wrapped as a ComposableFunction.

FLOOR

public static final ComposableFunction FLOOR

The FastMath.floor method wrapped as a ComposableFunction.

LOG

public static final ComposableFunction LOG

The FastMath.log method wrapped as a ComposableFunction.

LOG10

public static final ComposableFunction LOG10

The FastMath.log10 method wrapped as a ComposableFunction.

LOG1P

public static final ComposableFunction LOG1P

The FastMath.log1p method wrapped as a ComposableFunction.

COS

public static final ComposableFunction COS

The FastMath.cos method wrapped as a ComposableFunction.

ACOS

public static final ComposableFunction ACOS

The FastMath.abs method wrapped as a ComposableFunction.

COSH

public static final ComposableFunction COSH

The FastMath.cosh method wrapped as a ComposableFunction.

RINT

public static final ComposableFunction RINT

The FastMath.rint method wrapped as a ComposableFunction.

SIGNUM

public static final ComposableFunction SIGNUM

The FastMath.signum method wrapped as a ComposableFunction.

ULP

public static final ComposableFunction ULP

The FastMath.ulp method wrapped as a ComposableFunction.

Constructor Detail

ComposableFunction

public ComposableFunction()

Method Detail

of

public ComposableFunction of(UnivariateRealFunction f)

Precompose the instance with another function.

The composed function h created by h = g.of(f) is such that h.value(x) == g.value(f.value(x)) for all x.

Parameters:

f - function to compose with

Returns:

a new function which computes this.value(f.value(x))

See Also:

postCompose(UnivariateRealFunction)

postCompose

public ComposableFunction postCompose(UnivariateRealFunction f)

Postcompose the instance with another function.

The composed function h created by h = g.postCompose(f) is such that h.value(x) == f.value(g.value(x)) for all x.

Parameters:

f - function to compose with

Returns:

a new function which computes f.value(this.value(x))

See Also:

of(UnivariateRealFunction)

combine

public ComposableFunction combine(UnivariateRealFunction f,
                                  BivariateRealFunction combiner)

Return a function combining the instance and another function.

The function h created by h = g.combine(f, combiner) is such that h.value(x) == combiner.value(g.value(x), f.value(x)) for all x.

Parameters:

f - function to combine with the instance

combiner - bivariate function used for combining

Returns:

a new function which computes combine.value(this.value(x), f.value(x))

add

public ComposableFunction add(UnivariateRealFunction f)

Return a function adding the instance and another function.

Parameters:

f - function to combine with the instance

Returns:

a new function which computes this.value(x) + f.value(x)

add

public ComposableFunction add(double a)

Return a function adding a constant term to the instance.

Parameters:

a - term to add

Returns:

a new function which computes this.value(x) + a

subtract

public ComposableFunction subtract(UnivariateRealFunction f)

Return a function subtracting another function from the instance.

Parameters:

f - function to combine with the instance

Returns:

a new function which computes this.value(x) - f.value(x)

multiply

public ComposableFunction multiply(UnivariateRealFunction f)

Return a function multiplying the instance and another function.

Parameters:

f - function to combine with the instance

Returns:

a new function which computes this.value(x) * f.value(x)

multiply

public ComposableFunction multiply(double scaleFactor)

Return a function scaling the instance by a constant factor.

Parameters:

scaleFactor - constant scaling factor

Returns:

a new function which computes this.value(x) * scaleFactor

divide

public ComposableFunction divide(UnivariateRealFunction f)

Return a function dividing the instance by another function.

Parameters:

f - function to combine with the instance

Returns:

a new function which computes this.value(x) / f.value(x)

asCollector

public MultivariateRealFunction asCollector(BivariateRealFunction combiner,
                                            double initialValue)

Generates a function that iteratively apply instance function on all elements of an array.

The generated function behaves as follows:

• initialize result = initialValue
• iterate: result = combiner.value(result, this.value(nextMultivariateEntry));
• return result

Parameters:

combiner - combiner to use between entries

initialValue - initial value to use before first entry

Returns:

a new function that iteratively apply instance function on all elements of an array.

asCollector

public MultivariateRealFunction asCollector(BivariateRealFunction combiner)

Generates a function that iteratively apply instance function on all elements of an array.

Calling this method is equivalent to call asCollector(BivariateRealFunction, 0.0).

Parameters:

combiner - combiner to use between entries

Returns:

a new function that iteratively apply instance function on all elements of an array.

See Also:

asCollector(BivariateRealFunction, double)

asCollector

public MultivariateRealFunction asCollector(double initialValue)

Generates a function that iteratively apply instance function on all elements of an array.

Calling this method is equivalent to call asCollector(BinaryFunction.ADD, initialValue).

Parameters:

initialValue - initial value to use before first entry

Returns:

a new function that iteratively apply instance function on all elements of an array.

See Also:

asCollector(BivariateRealFunction, double), BinaryFunction.ADD

asCollector

public MultivariateRealFunction asCollector()

Generates a function that iteratively apply instance function on all elements of an array.

Calling this method is equivalent to call asCollector(BinaryFunction.ADD, 0.0).

Returns:

a new function that iteratively apply instance function on all elements of an array.

See Also:

asCollector(BivariateRealFunction, double), BinaryFunction.ADD

value

public abstract double value(double x)
                      throws FunctionEvaluationException

Compute the value for the function.

Specified by:

value in interface UnivariateRealFunction

Parameters:

x - the point for which the function value should be computed

Returns:

the value

Throws:

FunctionEvaluationException - if the function evaluation fails