broadwick.math

Class Vector

java.lang.Object

broadwick.math.Vector

public class Vector
extends Object

Implementation of mathematical vector (not to be confused with the data structure). It is perhaps best to think of this as a row-vector as several underlying operations (such as multiplying by a matrix) are implemented by casting the vector into a 1D (row) matrix which can be transposed etc internally.

Field Summary

Fields

Modifier and Type	Field and Description
private double[]	data

Constructor Summary

Constructors

Constructor and Description
Vector(double[] data) Copy constructor.
Vector(int dimension) Create a vector of a given dimension.
Vector(Vector v) Copy constructor.

Method Summary

Modifier and Type	Method and Description
Vector	add(Vector v) Add a vector to this one.
double	element(int i) Get the element at the given index.
int	length() Obtain the length, i.e.
double	multiply(Vector v) Calculate the dot product of this vector with v.
double	setEntry(int i, double value) Set the value of the vector at a given index.
Vector	subtract(Vector v) Subtract a vector from this one.
double[]	toArray() Return a copy of the vector as an array.
String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

data

private final double[] data

Constructor Detail

Vector

public Vector(int dimension)

Create a vector of a given dimension. Each element will be set to 0.

Parameters:

dimension - the dimension of the vector.

Vector

public Vector(Vector v)

Copy constructor.

Parameters:

v - the vector to be copied.

Vector

public Vector(double[] data)

Copy constructor.

Parameters:

data - an array that will be copied.

Method Detail

element

public double element(int i)

Get the element at the given index.

Parameters:

i - the vector element to be found.

Returns:

the vector element

setEntry

public double setEntry(int i,
                       double value)

Set the value of the vector at a given index.

Parameters:

i - the coordinate of the vector to be set

value - the value of the vector element.

Returns:

the updated value.

toArray

public double[] toArray()

Return a copy of the vector as an array.

Returns:

a copy of the vector as an array.

length

public int length()

Obtain the length, i.e. the number of components of this vector.

Returns:

the number of elements in the vector.

add

public Vector add(Vector v)

Add a vector to this one.

Parameters:

v - the vector to be added to this one.

Returns:

this (updated) vector.

subtract

public Vector subtract(Vector v)

Subtract a vector from this one.

Parameters:

v - the vector to be subtracted from this one.

Returns:

this (updated) vector.

multiply

public double multiply(Vector v)

Calculate the dot product of this vector with v.

Parameters:

v - the vector to be dotted.

Returns:

this (updated) vector.

toString

public String toString()

Overrides:

toString in class Object