edu.ucla.sspace.vector

Class VectorMath

java.lang.Object

edu.ucla.sspace.vector.VectorMath

public class VectorMath
extends Object

A collection of static arithmetic operations on Vector instances.

The methods of this class all throw a NullPointerException if the Vector objects provided to them are null.

Author:

Keith Stevens

Method Summary

Methods

Modifier and Type	Method and Description
static DoubleVector	add(DoubleVector vector1, DoubleVector vector2) Adds the second DoubleVector to the first DoubleVector and returns the result.
static IntegerVector	add(IntegerVector vector1, IntegerVector vector2) Adds the second IntegerVector to the first IntegerVector and returns the result.
static Vector	add(Vector vector1, Vector vector2) Adds the second Vector to the first Vector and returns the result.
static DoubleVector	addUnmodified(DoubleVector vector1, DoubleVector vector2) Returns a new DoubleVector which is the summation of vector2 and vector1.
static IntegerVector	addUnmodified(IntegerVector vector1, IntegerVector vector2) Returns a new IntegerVector which is the summation of vector2 and vector1.
static Vector	addUnmodified(Vector vector1, Vector vector2) Returns a new Vector which is the summation of vector2 and vector1.
static Vector	addWithScalars(DoubleVector vector1, double weight1, DoubleVector vector2, double weight2) Adds two DoubleVectors with some scalar weight for each DoubleVector.
static Vector	addWithScalars(IntegerVector vector1, int weight1, IntegerVector vector2, int weight2) Adds two IntegerVectors with some scalar weight for each Vector.
static Vector	addWithScalars(Vector vector1, double weight1, Vector vector2, double weight2) Adds two Vectors with some scalar weight for each Vector.
static double	dotProduct(DoubleVector a, DoubleVector b) Computes the dot product, aTb of the two vectors.
static int	dotProduct(IntegerVector a, IntegerVector b) Computes the dot product, aTb of the two vectors.
static double	dotProduct(Vector x, Vector y) Computes the dot product, xTy of the two vectors.
static DoubleVector	multiply(DoubleVector left, DoubleVector right) Multiply the values in left and right and store the product in left.
static IntegerVector	multiply(IntegerVector left, IntegerVector right) Multiply the values in left and right and store the product in left.
static Vector	multiply(Vector left, Vector right) Mulitplies the values in left and right and store the product in left.
static DoubleVector	multiplyUnmodified(DoubleVector left, DoubleVector right) Multiply the values in left and right and store the product in a new Vector.
static SparseDoubleVector	multiplyUnmodified(SparseDoubleVector a, SparseDoubleVector b) Multiply the values in a and b and store the product in a new CompactSparseVector This is an element by element multiplication.
static DoubleVector	subtract(DoubleVector vector1, DoubleVector vector2) Subtracts the second DoubleVector from the first DoubleVector and returns the result.
static IntegerVector	subtract(IntegerVector vector1, IntegerVector vector2) Subtracts the second IntegerVector from the first IntegerVector and returns the result.
static Vector	subtract(Vector vector1, Vector vector2) Subtracts the second Vector fromt the first Vector and returns the result.

Methods inherited from class java.lang.Object

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

Method Detail

add

public static Vector add(Vector vector1,
         Vector vector2)

Adds the second Vector to the first Vector and returns the result.

Parameters:

vector1 - The destination vector to be summed onto.

vector2 - The source vector to sum from.

Returns:

The summation of {code vector1} and vector2.

add

public static DoubleVector add(DoubleVector vector1,
               DoubleVector vector2)

Adds the second DoubleVector to the first DoubleVector and returns the result.

Parameters:

vector1 - The destination vector to be summed onto.

vector2 - The source vector to sum from.

Returns:

The summation of {code vector1} and vector2.

add

public static IntegerVector add(IntegerVector vector1,
                IntegerVector vector2)

Adds the second IntegerVector to the first IntegerVector and returns the result.

Parameters:

vector1 - The destination vector to be summed onto.

vector2 - The source vector to sum from.

Returns:

The summation of {code vector1} and vector2.

addUnmodified

public static Vector addUnmodified(Vector vector1,
                   Vector vector2)

Returns a new Vector which is the summation of vector2 and vector1.

Parameters:

vector1 - The first vector to used in a summation.

vector2 - The second vector to be used in a summation.

Returns:

The summation of {code vector1} and vector2.

addUnmodified

public static DoubleVector addUnmodified(DoubleVector vector1,
                         DoubleVector vector2)

Returns a new DoubleVector which is the summation of vector2 and vector1.

Parameters:

vector1 - The first vector to used in a summation.

vector2 - The second vector to be used in a summation.

Returns:

The summation of {code vector1} and vector2.

addUnmodified

public static IntegerVector addUnmodified(IntegerVector vector1,
                          IntegerVector vector2)

Returns a new IntegerVector which is the summation of vector2 and vector1.

Parameters:

vector1 - The first vector to used in a summation.

vector2 - The second vector to be used in a summation.

Returns:

The summation of vector1 and vector2.

addWithScalars

public static Vector addWithScalars(Vector vector1,
                    double weight1,
                    Vector vector2,
                    double weight2)

Adds two Vectors with some scalar weight for each Vector.

Parameters:

vector1 - The vector values should be added to.

weight1 - The weight of values in vector1

vector2 - The vector values that should be added to vector1

weight2 - The weight of values in vector2

{@code - vector1}

addWithScalars

public static Vector addWithScalars(DoubleVector vector1,
                    double weight1,
                    DoubleVector vector2,
                    double weight2)

Adds two DoubleVectors with some scalar weight for each DoubleVector.

Parameters:

vector1 - The vector values should be added to.

weight1 - The weight of values in vector1

vector2 - The vector values that should be added to vector1

weight2 - The weight of values in vector2

{@code - vector1}

addWithScalars

public static Vector addWithScalars(IntegerVector vector1,
                    int weight1,
                    IntegerVector vector2,
                    int weight2)

Adds two IntegerVectors with some scalar weight for each Vector.

Parameters:

vector1 - The vector values should be added to.

weight1 - The weight of values in vector1

vector2 - The vector values that should be added to vector1

weight2 - The weight of values in vector2

{@code - vector1}

dotProduct

public static double dotProduct(Vector x,
                Vector y)

Computes the dot product, x^Ty of the two vectors.

Parameters:

x - the left vector that will be transposed

y - the right vector

Returns:

the dot product of the two vectors.

Throws:

IllegalArgumentException - if the two vectors are not of equal length

dotProduct

public static double dotProduct(DoubleVector a,
                DoubleVector b)

Computes the dot product, a^Tb of the two vectors.

Parameters:

a - the left vector that will be transposed

b - the right vector

Returns:

the dot product of the two vectors.

Throws:

IllegalArgumentException - if the two vectors are not of equal length

dotProduct

public static int dotProduct(IntegerVector a,
             IntegerVector b)

Computes the dot product, a^Tb of the two vectors.

Parameters:

a - the left vector that will be transposed

b - the right vector

Returns:

the dot product of the two vectors.

Throws:

IllegalArgumentException - if the two vectors are not of equal length

multiply

public static Vector multiply(Vector left,
              Vector right)

Mulitplies the values in left and right and store the product in left. This is an element by element multiplication.

Parameters:

left - The left Vector to multiply, and contain the result values.

right - The right Vector to multiply.

Returns:

The product of left and right

multiply

public static DoubleVector multiply(DoubleVector left,
                    DoubleVector right)

Multiply the values in left and right and store the product in left. This is an element by element multiplication.

Parameters:

left - The left Vector to multiply, and contain the result values.

right - The right Vector to multiply.

Returns:

The product of left and right

multiplyUnmodified

public static SparseDoubleVector multiplyUnmodified(SparseDoubleVector a,
                                    SparseDoubleVector b)

Multiply the values in a and b and store the product in a new CompactSparseVector This is an element by element multiplication.

Parameters:

a - The left Vector to multiply

b - The right Vector to multiply.

Returns:

The product of left and right

multiply

public static IntegerVector multiply(IntegerVector left,
                     IntegerVector right)

Multiply the values in left and right and store the product in left. This is an element by element multiplication.

Parameters:

left - The left Vector to multiply, and contain the result values.

right - The right Vector to multiply.

Returns:

The product of left and right

multiplyUnmodified

public static DoubleVector multiplyUnmodified(DoubleVector left,
                              DoubleVector right)

Multiply the values in left and right and store the product in a new Vector. This is an element by element multiplication.

Parameters:

left - The left Vector to multiply.

right - The right Vector to multiply.

Returns:

The product of left and right

subtract

public static Vector subtract(Vector vector1,
              Vector vector2)

Subtracts the second Vector fromt the first Vector and returns the result.

Parameters:

vector1 - The destination vector to be subtracted from.

vector2 - The source vector to subtract.

Returns:

The subtraction of {code vector2} from vector1.

subtract

public static DoubleVector subtract(DoubleVector vector1,
                    DoubleVector vector2)

Subtracts the second DoubleVector from the first DoubleVector and returns the result.

Parameters:

vector1 - The destination vector to be subtracted from.

vector2 - The source vector to subtract.

Returns:

The subtraction of {code vector2} from vector1.

subtract

public static IntegerVector subtract(IntegerVector vector1,
                     IntegerVector vector2)

Subtracts the second IntegerVector from the first IntegerVector and returns the result.

Parameters:

vector1 - The destination vector to be subtracted from.

vector2 - The source vector to subtract.

Returns:

The subtraction of {code vector2} from vector1.