Package pulse.math.linear

Class Vector

java.lang.Object

pulse.math.linear.Vector

All Implemented Interfaces:

Serializable

public class Vector
extends Object
implements Serializable

This is a general class for Vector operations useful for optimisers and ODE solvers.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor	Description
Vector(double[] x)	Constructs a new vector specified by the argument array
Vector(int n)	Creates a zero Vector.
Vector(Vector v)	Copy constructor.

Method Summary

Modifier and Type	Method	Description
int	dimension()	The dimension is simply the number of elements in a Vector
double	distanceToSq(Vector v)	Calculates the squared distance from this Vector to v (which is the squared length of the connecting Vector).
double	dot(Vector v)	Calculates the scalar product of this and v.
boolean	equals(Object o)	Checks if o is logically equivalent to an instance of this class.
double	get(int index)	Gets the component of this Vector specified by index
double[]	getData()
Vector	inverted()	Creates a new Vector based on this one, all elements of which are inverted, i.e.
double	length()	Calculates the length, which is represented by the square-root of the squared length.
double	lengthSq()	The squared length of this vector is the dot product of this vector by itself.
double	maxAbsComponent()	Determines the maximum absolute value of the vector components.
Vector	multComponents(Vector v)	Component-wise vector multiplication
Vector	multiply(double f)	Performs an element-wise multiplication by f.
Vector	normalise()	Performs normalisation, e.g.
static Vector	random(int n, double min, double max)	Creates a vector with random coordinates confined within [min;max]
void	set(int index, double value)	Sets the component of this Vector specified by index to value.
Vector	subtract(Vector v)	Performs an element-wise subtraction of v from this.
Vector	sum(Vector v)	Performs an element-wise summation of this and v.
String	toString()	Defines the string representation of the current instance of the class.

Methods inherited from class java.lang.Object

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

Constructor Detail

Vector

public Vector(double[] x)

Constructs a new vector specified by the argument array

Parameters:

x - an array of double

Vector

public Vector(int n)

Creates a zero Vector.

Parameters:

n - the dimension of the Vector.

Vector

public Vector(Vector v)

Copy constructor.

Parameters:

v - The vector to be copied

Method Detail

inverted

public Vector inverted()

Creates a new Vector based on this one, all elements of which are inverted, i.e. $$b_i = -a_i.

Returns:

a generalised inversion of this Vector.

dimension

public final int dimension()

The dimension is simply the number of elements in a Vector

Returns:

the integer dimension

sum

public Vector sum(Vector v)

Performs an element-wise summation of this and v.

Parameters:

v - another Vector with the same number of elements.

Returns:

the result of the summation.

subtract

public Vector subtract(Vector v)

Performs an element-wise subtraction of v from this.

Parameters:

v - another Vector with the same number of elements.

Returns:

the result of subtracting v from this.

Throws:

IllegalArgumentException - f the dimension of this and v are different.

multiply

public Vector multiply(double f)

Performs an element-wise multiplication by f.

Parameters:

f - a double value.

Returns:

a new Vector, all elements of which will be multiplied by f.

random

public static Vector random(int n,
                            double min,
                            double max)

Creates a vector with random coordinates confined within [min;max]

Parameters:

n - the vector dimension

min - upper bound for the random number generator

max - lower bound for the random generator generator

Returns:

the randomised vector

multComponents

public Vector multComponents(Vector v)

Component-wise vector multiplication

dot

public double dot(Vector v)

Calculates the scalar product of this and v.

Parameters:

v - another Vector with the same dimension.

Returns:

the dot product of this and v.

length

public double length()

Calculates the length, which is represented by the square-root of the squared length.

Returns:

the calculated length.

See Also:

lengthSq()

lengthSq

public double lengthSq()

The squared length of this vector is the dot product of this vector by itself.

Returns:

the squared length.

normalise

public Vector normalise()

Performs normalisation, e.g. scalar multiplication of this by the multiplicative inverse of this Vector's length.

Returns:

a normalised Vector obtained from this.

distanceToSq

public double distanceToSq(Vector v)
                    throws IllegalArgumentException

Calculates the squared distance from this Vector to v (which is the squared length of the connecting Vector).

Parameters:

v - another Vector.

Returns:

the squared length of the connecting Vector.

Throws:

IllegalArgumentException - f the dimension of this and v are different.

get

public double get(int index)

Gets the component of this Vector specified by index

Parameters:

index - the index of the component

Returns:

a double value, representing the value of the component

set

public void set(int index,
                double value)

Sets the component of this Vector specified by index to value.

Parameters:

index - the index of the component.

value - a new value that will replace the old one.

toString

public String toString()

Defines the string representation of the current instance of the class.

Overrides:

toString in class Object

Returns:

the string-equivalent of this object containing all it's field values.

equals

public boolean equals(Object o)

Checks if o is logically equivalent to an instance of this class.

Overrides:

equals in class Object

Parameters:

o - An object to compare with this vector.

Returns:

true if o equals this.

maxAbsComponent

public double maxAbsComponent()

Determines the maximum absolute value of the vector components.

Returns:

a component having the maximum absolute value.

getData

public double[] getData()