jsat.linear

Class ShiftedVec

java.lang.Object

jsat.linear.Vec

jsat.linear.ShiftedVec

All Implemented Interfaces:

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

public class ShiftedVec
extends Vec

A wrapper for a vector that represents the vector added with a scalar value. This allows for using and altering the value added by a constant factor quickly. Mutable operations will alter the underling vector, and all operations will automatically be adjusted on a per element basis as needed. The most significant performance difference is in representing a sparse input sifted by a constant factor. Note, that when using a sparse base vector - the ShiftedVec will always return true for isSparse(), even if shifting makes all values non-zero

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
ShiftedVec(Vec base, double shift) Creates a new vector represented as base+shift

Method Summary

Modifier and Type	Method and Description
ShiftedVec	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.
void	embedShift() Embeds the current shift scalar into the base vector, modifying it and then setting the new shit to zero.
double	get(int index) Gets the value stored at a specific index in the vector
Vec	getBase()
java.util.Iterator<IndexValue>	getNonZeroIterator(int start) Returns an iterator that will go over the non zero values starting from the specified index in the given vector.
double	getShift()
void	increment(int index, double val) Increments the value stored at a specified 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.
double	kurtosis() Computes the kurtosis of this vector, which is the 4th moment.
int	length() Returns the length of this vector
double	max() Returns the maximum value stored in this vector
double	mean() Computes the mean value of all values stored in this vector
double	median() Returns the median value in this vector
double	min() Returns the minimum value stored in this vector
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	mutableAdd(Vec b) Alters this vector such that this = this + b
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.
double	pNorm(double p) Returns the p-norm of this vector.
void	set(int index, double val) Sets the value stored at a specified index in the vector
void	setShift(double shift) Directly alters the shift value used for this vector.
double	standardDeviation() Computes the standard deviation of the values in this vector
double	variance() Computes the variance of the values in this vector, which is Vec.standardDeviation()2
void	zeroOut() Zeroes out all values in this vector This method should be overloaded for a serious implementation.

Methods inherited from class jsat.linear.Vec

add, add, applyFunction, applyIndexFunction, arrayCopy, canBeMutated, copyTo, copyToCol, copyToRow, countNaNs, divide, equals, equals, getNonZeroIterator, hashCode, iterator, multiply, multiply, multiply, multiply, mutableSubtract, mutableSubtract, mutableSubtract, nnz, normalize, normalized, pairwiseDivide, pairwiseMultiply, pNormDist, random, random, skewness, sortedCopy, subtract, subtract, sum, toString, 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

ShiftedVec

public ShiftedVec(Vec base,
                  double shift)

Creates a new vector represented as base+shift

Parameters:

base - the base vector to represent

shift - the scalar shift to add to the base vector

Method Detail

getBase

public Vec getBase()

Returns:

the base vector used by this object

setShift

public void setShift(double shift)

Directly alters the shift value used for this vector. The old sift is "forgotten" immediately.

Parameters:

shift - the new value to use for the additive scalar

getShift

public double getShift()

Returns:

the additive scalar used to shift over the base value

embedShift

public void embedShift()

Embeds the current shift scalar into the base vector, modifying it and then setting the new shit to zero. This makes the base vector have the value represented by this ShiftedVec

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

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

increment

public void increment(int index,
                      double val)

Description copied from class: Vec

Increments the value stored at a specified index in the vector

Overrides:

increment in class Vec

Parameters:

index - the index to access

val - the value to store in the index

mutableAdd

public void mutableAdd(Vec b)

Description copied from class: Vec

Alters this vector such that this = this + b

Overrides:

mutableAdd in class Vec

Parameters:

b - the vector to add to this

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

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

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

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

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

zeroOut

public void zeroOut()

Description copied from class: Vec

Zeroes out all values in this vector

This method should be overloaded for a serious implementation.

Overrides:

zeroOut in class Vec

pNorm

public double pNorm(double p)

Description copied from class: Vec

Returns the p-norm of this vector.

Overrides:

pNorm in class Vec

Parameters:

p - the norm type. 2 is a common value

Returns:

the p-norm of this vector

mean

public double mean()

Description copied from class: Vec

Computes the mean value of all values stored in this vector

Overrides:

mean in class Vec

Returns:

the mean value

variance

public double variance()

Description copied from class: Vec

Computes the variance of the values in this vector, which is Vec.standardDeviation()²

Overrides:

variance in class Vec

Returns:

the variance

standardDeviation

public double standardDeviation()

Description copied from class: Vec

Computes the standard deviation of the values in this vector

Overrides:

standardDeviation in class Vec

Returns:

the standard deviation

kurtosis

public double kurtosis()

Description copied from class: Vec

Computes the kurtosis of this vector, which is the 4th moment.

Overrides:

kurtosis in class Vec

Returns:

the kurtosis

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

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

median

public double median()

Description copied from class: Vec

Returns the median value in this vector

Overrides:

median in class Vec

Returns:

the median

getNonZeroIterator

public java.util.Iterator<IndexValue> getNonZeroIterator(int start)

Description copied from class: Vec

Returns an iterator that will go over the non zero values starting from the specified index in the given vector. The iterator does not support the Iterator.remove() method.

This method should be overloaded for a serious implementation.

Overrides:

getNonZeroIterator in class Vec

Parameters:

start - the first index (inclusive) to start returning non-zero values from

Returns:

an iterator for the non zero index value pairs

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 ShiftedVec clone()

Specified by:

clone in class Vec