jsat.linear

Class RandomVector

java.lang.Object

jsat.linear.Vec

jsat.linear.RandomVector

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable, java.lang.Iterable<IndexValue>

public abstract class RandomVector
extends Vec

Stores a Vector full of random values in constant O(1) space by re-computing all matrix values on the fly as need. This allows memory reduction and use when it is necessary to use the matrix with a large sparse data set, where some matrix values may never even be used - or used very infrequently.

Because the values of the random vector are computed on the fly, the Random Vector can not be altered. If attempted, an exception will be thrown.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
RandomVector(int length) Creates a new Random Vector object
RandomVector(int length, long seedMult) Creates a new Random Vector object

Method Summary

Modifier and Type	Method and Description
boolean	canBeMutated() Indicates whether or not this vector can be mutated.
abstract Vec	clone()
double	dot(Vec v) Computes the dot product between two vectors, which is equivalent to Σ thisi*vi This method should be overloaded for a serious implementation.
double	get(int index) Gets the value stored at a specific index in the vector
boolean	isSparse() Indicates whether or not this vector is optimized for sparce computation, meaning that most values in the vector are zero - and considered implicit.
int	length() Returns the length of this vector
double	max() Returns the maximum value stored in this vector
double	min() Returns the minimum value stored in this vector
void	multiply(double c, Matrix A, Vec b) If this is vector a, this this computes b = b + c aT*A
void	mutableAdd(double c) Alters this vector such that this = this + c This method should be overloaded for a serious implementation.
void	mutableAdd(double c, Vec b) Alters this vector such that this = this + c * b This method should be overloaded for a serious implementation.
void	mutableDivide(double c) Mutates this /= c This method should be overloaded for a serious implementation.
void	mutableMultiply(double c) Mutates this *= c This method should be overloaded for a serious implementation.
void	mutablePairwiseDivide(Vec b) Mutates this by dividing each value by the value in b that has the same index This method should be overloaded for a serious implementation.
void	mutablePairwiseMultiply(Vec b) Mutates this by multiplying each value by the value in b that has the same index.
void	set(int index, double val) Sets the value stored at a specified index in the vector
Vec	sortedCopy() Returns a copy of this array with the values moved around so that they are in sorted order

Methods inherited from class jsat.linear.Vec

add, add, applyFunction, applyIndexFunction, arrayCopy, copyTo, copyToCol, copyToRow, countNaNs, divide, equals, equals, getNonZeroIterator, getNonZeroIterator, hashCode, increment, iterator, kurtosis, mean, median, multiply, multiply, multiply, mutableAdd, mutableSubtract, mutableSubtract, mutableSubtract, nnz, normalize, normalized, pairwiseDivide, pairwiseMultiply, pNorm, pNormDist, random, random, skewness, standardDeviation, subtract, subtract, sum, toString, variance, zeroOut, zeros

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Detail

RandomVector

public RandomVector(int length)

Creates a new Random Vector object

Parameters:

length - the length of the vector

RandomVector

public RandomVector(int length,
                    long seedMult)

Creates a new Random Vector object

Parameters:

length - the length of the vector

seedMult - a value to multiply with the seed used for each individual index. It should be a large value

Method Detail

get

public double get(int index)

Description copied from class: Vec

Gets the value stored at a specific index in the vector

Specified by:

get in class Vec

Parameters:

index - the index to access

Returns:

the double value in the vector

set

public void set(int index,
                double val)

Description copied from class: Vec

Sets the value stored at a specified index in the vector

Specified by:

set in class Vec

Parameters:

index - the index to access

val - the value to store in the index

length

public int length()

Description copied from class: Vec

Returns the length of this vector

Specified by:

length in class Vec

Returns:

the length of this vector

multiply

public void multiply(double c,
                     Matrix A,
                     Vec b)

Description copied from class: Vec

If this is vector a, this this computes b = b + c a^T*A

Overrides:

multiply in class Vec

Parameters:

c - the constant factor to multiply by

A - the matrix to multiple by

b - the vector to mutate by adding the result to

mutableAdd

public void mutableAdd(double c)

Description copied from class: Vec

Alters this vector such that this = this + c

This method should be overloaded for a serious implementation.

Overrides:

mutableAdd in class Vec

Parameters:

c - a scalar constant to add to each value in this vector

mutableAdd

public void mutableAdd(double c,
                       Vec b)

Description copied from class: Vec

Alters this vector such that this = this + c * b

This method should be overloaded for a serious implementation.

Overrides:

mutableAdd in class Vec

Parameters:

c - a scalar constant

b - the vector to add to this

mutablePairwiseMultiply

public void mutablePairwiseMultiply(Vec b)

Description copied from class: Vec

Mutates this by multiplying each value by the value in b that has the same index.

This method should be overloaded for a serious implementation.

Overrides:

mutablePairwiseMultiply in class Vec

Parameters:

b - the vector to pairwise multiply by

mutableMultiply

public void mutableMultiply(double c)

Description copied from class: Vec

Mutates this *= c

This method should be overloaded for a serious implementation.

Overrides:

mutableMultiply in class Vec

Parameters:

c - the constant to multiply by

mutablePairwiseDivide

public void mutablePairwiseDivide(Vec b)

Description copied from class: Vec

Mutates this by dividing each value by the value in b that has the same index

This method should be overloaded for a serious implementation.

Overrides:

mutablePairwiseDivide in class Vec

Parameters:

b - the vector to pairwise divide by

mutableDivide

public void mutableDivide(double c)

Description copied from class: Vec

Mutates this /= c

This method should be overloaded for a serious implementation.

Overrides:

mutableDivide in class Vec

Parameters:

c - the constant to divide by

sortedCopy

public Vec sortedCopy()

Description copied from class: Vec

Returns a copy of this array with the values moved around so that they are in sorted order

Overrides:

sortedCopy in class Vec

Returns:

a new array in sorted order

min

public double min()

Description copied from class: Vec

Returns the minimum value stored in this vector

Overrides:

min in class Vec

Returns:

the minimum value in this vector

max

public double max()

Description copied from class: Vec

Returns the maximum value stored in this vector

Overrides:

max in class Vec

Returns:

the maximum value in this vector

isSparse

public boolean isSparse()

Description copied from class: Vec

Indicates whether or not this vector is optimized for sparce computation, meaning that most values in the vector are zero - and considered implicit. Only non-zero values are stored.

Specified by:

isSparse in class Vec

Returns:

true if the vector is sparce, false otherwise.

clone

public abstract Vec clone()

Specified by:

clone in class Vec

dot

public double dot(Vec v)

Description copied from class: Vec

Computes the dot product between two vectors, which is equivalent to
Σ this_i*v_i

This method should be overloaded for a serious implementation.

Overrides:

dot in class Vec

Parameters:

v - the other vector

Returns:

the dot product of this vector and another

canBeMutated

public boolean canBeMutated()

Description copied from class: Vec

Indicates whether or not this vector can be mutated. If false, any method that contains "mutate" will not work.

By default, this returns true

Overrides:

canBeMutated in class Vec

Returns:

true if the vector supports being altered, false other wise.