cat.lump.aq.basics.algebra.vector

Class Vector

java.lang.Object

cat.lump.aq.basics.algebra.vector.Vector

All Implemented Interfaces:

java.io.Serializable

public class Vector
extends java.lang.Object
implements java.io.Serializable

A vector of doubles that allows for a number of vector-vector and vector-scalar algebraic operations, including:

• sum of vectors (--> vector)
• product of vectors (--> scalar)
• product by scalar (--> vector)
• division by scalar (--> vector)

Properties of the vector ---magnitude, max, min, argmax, and argmin--- are available as well.
This class is partially inspired by Jama

Since:

April 26 2012

Version:

0.2

Author:

albarron

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
Vector(float[] values) Initialisation with an array of doubles

Method Summary

Methods

Modifier and Type	Method and Description
float[]	add(float[] values) Sums the contents of vector to values and returns the result This method does not modify the vector.
Vector	add(Vector v) Sums the contents of v to vector This method does not modify the vector.
void	addEquals(float[] values) Sums the values to vector, modifying its contents.
void	addEquals(Vector v) Sums v2 to vector and store the result in the vector itself.
int	argmax()
int	argmin()
float[]	divide(float value) Divides the vector by a scalar and returns the resulting array.
void	divideEquals(float value) Divides the vector by a scalar and updates its value internally.
float	dotProduct(float[] values) Computes the dot product between the vector and an array of doubles.
float	dotProduct(Vector v) Computes the dot product between the vector and vector v2.
float[]	get()
float	get(int index)
int	length()
float	magnitude() Computes the magnitude of the vector (aka norm).
float	max()
float	min()
boolean	sameCardinality(float[] v2) Check if the vector and v2 have the same cardinality.
boolean	sameCardinality(Vector v) Check if the vector and v2 have the same cardinality.
float[]	times(float value) Multiplies the vector times a scalar and returns the result.
void	timesEquals(float value) Multiplies the vector times a scalar and updates its internal value.

Methods inherited from class java.lang.Object

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

Constructor Detail

Vector

public Vector(float[] values)

Initialisation with an array of doubles

Parameters:

values -

Method Detail

add

public Vector add(Vector v)

Sums the contents of v to vector
This method does not modify the vector.

Parameters:

v -

Returns:

vector + v

add

public float[] add(float[] values)

Sums the contents of vector to values and returns the result
This method does not modify the vector.

Parameters:

values -

Returns:

vector + values

addEquals

public void addEquals(Vector v)

Sums v2 to vector and store the result in the vector itself.
This method modifies the internal values of the vector.

Parameters:

v -

addEquals

public void addEquals(float[] values)

Sums the values to vector, modifying its contents.
This method modifies the internal values of the vector.

Parameters:

values -

dotProduct

public float dotProduct(Vector v)

Computes the dot product between the vector and vector v2.
Note that v must have the same length as the vector.

Parameters:

v -

Returns:

dotproduct(vector, v)

dotProduct

public float dotProduct(float[] values)

Computes the dot product between the vector and an array of doubles.
Note that the array must have the same length as the vector.

Parameters:

values -

Returns:

dotproduct(vector, values)

times

public float[] times(float value)

Multiplies the vector times a scalar and returns the result.

Parameters:

value -

Returns:

vector * value

timesEquals

public void timesEquals(float value)

Multiplies the vector times a scalar and updates its internal value.
This method modifies the internal values of the vector.

Parameters:

value -

divide

public float[] divide(float value)

Divides the vector by a scalar and returns the resulting array.

Parameters:

value -

Returns:

vector / d

divideEquals

public void divideEquals(float value)

Divides the vector by a scalar and updates its value internally.
This method modifies the internal values of the vector.

Parameters:

value -

magnitude

public float magnitude()

Computes the magnitude of the vector (aka norm).

Returns:

magnitude of the vector

max

public float max()

Returns:

maximum numerical value in the vector.

argmax

public int argmax()

Returns:

argument of the maximum numerical value in the vector.

min

public float min()

Returns:

minimum numerical value in the vector.

argmin

public int argmin()

Returns:

argument of the minimum value in the vector.

get

public float[] get()

Returns:

array of the vector

get

public float get(int index)

Parameters:

index -

Returns:

the value at a particular index

Throws:

java.lang.NullPointerException

length

public int length()

Returns:

length of the vector

sameCardinality

public boolean sameCardinality(Vector v)

Check if the vector and v2 have the same cardinality.

Parameters:

v -

Returns:

true if card(vector)=card(v)

sameCardinality

public boolean sameCardinality(float[] v2)

Check if the vector and v2 have the same cardinality.

Parameters:

v2 -

Returns:

true if card(vector)=card(v2)