Package org.opentrafficsim.core.distributions

Class Distribution<O>

java.lang.Object

org.opentrafficsim.core.distributions.Distribution<O>

Type Parameters:

O - Type of the object returned by the draw method

All Implemented Interfaces:

java.io.Serializable, Generator<O>

public class Distribution<O>
extends java.lang.Object
implements Generator<O>, java.io.Serializable

Generic implementation of a set of objects that have a draw method with corresponding probabilities / frequencies.

Copyright (c) 2013-2020 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved.
BSD-style license. See OpenTrafficSim License.

Version:

$Revision$, $LastChangedDate$, by $Author$, initial version Mar 1, 2016

Author:

Peter Knoppers

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	Distribution.FrequencyAndObject<O>	Immutable storage for a frequency (or probability) plus a Generator.

Constructor Summary

Constructors

Constructor	Description
Distribution(java.util.List<Distribution.FrequencyAndObject<O>> generators, StreamInterface stream)	Construct a new Distribution.
Distribution(StreamInterface stream)	Construct a new Distribution with no generators.

Method Summary

Modifier and Type	Method	Description
Distribution<O>	add(int index, Distribution.FrequencyAndObject<O> generator)	Insert a generator at the specified position in the internally stored list.
Distribution<O>	add(Distribution.FrequencyAndObject<O> generator)	Append a generator to the internally stored list.
Distribution<O>	clear()	Empty the internally stored list.
O	draw()	Generate the next object.
boolean	equals(java.lang.Object obj)
Distribution.FrequencyAndObject<O>	get(int index)	Retrieve one of the internally stored generators.
int	hashCode()
Distribution<O>	modifyFrequency(int index, double frequency)	Alter the frequency (or probability) of one of the stored generators.
Distribution<O>	remove(int index)	Remove the generator at the specified position from the internally stored list.
Distribution<O>	set(int index, Distribution.FrequencyAndObject<O> generator)	Replace the generator at the specified position.
int	size()	Report the number of generators.
java.lang.String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

Distribution

public Distribution(java.util.List<Distribution.FrequencyAndObject<O>> generators,
                    StreamInterface stream)
             throws ProbabilityException

Construct a new Distribution.

Parameters:

generators - List<FrequencyAndObject<O>>; the generators and their frequencies (or probabilities)

stream - StreamInterface; source for randomness

Throws:

ProbabilityException - when a frequency (or probability) is negative, or when generators is null or stream is null

Distribution

public Distribution(StreamInterface stream)
             throws ProbabilityException

Construct a new Distribution with no generators.

Parameters:

stream - StreamInterface; source for randomness

Throws:

ProbabilityException - when a frequency (or probability) is negative, or when generators is null or stream is null

Method Detail

draw

public final O draw()
             throws ProbabilityException

Generate the next object.

Specified by:

draw in interface Generator<O>

Returns:

O; an object randomly selected from the stored collection

Throws:

ProbabilityException - if the stored collection is empty

add

public final Distribution<O> add(Distribution.FrequencyAndObject<O> generator)
                          throws ProbabilityException

Append a generator to the internally stored list.

Parameters:

generator - FrequencyAndObject<O>; the generator to add

Returns:

Distribution<O>; this

Throws:

ProbabilityException - when frequency less than zero

add

public final Distribution<O> add(int index,
                                 Distribution.FrequencyAndObject<O> generator)
                          throws ProbabilityException

Insert a generator at the specified position in the internally stored list.

Parameters:

index - int; position to store the generator

generator - FrequencyAndObject<O>; the generator to add

Returns:

Distribution<O>; this

Throws:

ProbabilityException - when frequency less than zero

remove

public final Distribution<O> remove(int index)
                             throws java.lang.IndexOutOfBoundsException,
                                    ProbabilityException

Remove the generator at the specified position from the internally stored list.

Parameters:

index - int; the position

Returns:

this

Throws:

java.lang.IndexOutOfBoundsException - when index is < 0 or >= size

ProbabilityException - if the sum of the remaining probabilities or frequencies adds up to 0

set

public final Distribution<O> set(int index,
                                 Distribution.FrequencyAndObject<O> generator)
                          throws ProbabilityException

Replace the generator at the specified position.

Parameters:

index - int; the position of the generator that must be replaced

generator - FrequencyAndObject<O>; the new generator and the frequency (or probability)

Returns:

this

Throws:

ProbabilityException - when the frequency (or probability) < 0, or when index is < 0 or >= size

modifyFrequency

public final Distribution<O> modifyFrequency(int index,
                                             double frequency)
                                      throws ProbabilityException

Alter the frequency (or probability) of one of the stored generators.

Parameters:

index - int; index of the stored generator

frequency - double; new frequency (or probability)

Returns:

this

Throws:

ProbabilityException - when the frequency (or probability) < 0, or when index is < 0 or >= size

clear

public final Distribution<O> clear()

Empty the internally stored list.

Returns:

this

get

public final Distribution.FrequencyAndObject<O> get(int index)
                                             throws ProbabilityException

Retrieve one of the internally stored generators.

Parameters:

index - int; the index of the FrequencyAndObject to retrieve

Returns:

FrequencyAndObject<O>; the generator stored at position index

Throws:

ProbabilityException - when index < 0 or >= size()

size

public final int size()

Report the number of generators.

Returns:

int; the number of generators

hashCode

public final int hashCode()

Overrides:

hashCode in class java.lang.Object

equals

public final boolean equals(java.lang.Object obj)

Overrides:

equals in class java.lang.Object

toString

public final java.lang.String toString()

Overrides:

toString in class java.lang.Object