dev.nm.algebra.linear.vector.doubles.operation

Class VectorFactory

java.lang.Object

dev.nm.algebra.linear.vector.doubles.operation.VectorFactory

public class VectorFactory
extends Object

These are the utility functions that create new instances of vectors from existing ones.

Method Summary

Modifier and Type	Method and Description
static Vector	concat(Collection<Vector> vectors) Concatenates an array of vectors into one vector.
static SparseVector	concat(SparseVector... vectors) Concatenates an array of sparse vectors into one sparse vector.
static Vector	concat(Vector... vectors) Concatenates an array of vectors into one vector.
static Vector[]	cumsum(Vector[] arr) Gets the cumulative sums.
static Vector	diagonal(Matrix A) Gets the diagonal of a matrix as a vector.
static SparseVector	diagonal(SparseMatrix A) Gets the diagonal of a sparse matrix as a sparse vector.
static SparseVector	foreach(SparseVector vector, UnivariateRealFunction f) Constructs a new vector in which each entry is the result of applying a function to the corresponding entry of a sparse vector.
static Vector	foreach(Vector vector, DoubleUnaryOperator f) Constructs a new vector in which each entry is the result of applying a function to the corresponding entry of a vector.
static Vector	foreach(Vector vector, UnivariateRealFunction f) Constructs a new vector in which each entry is the result of applying a function to the corresponding entry of a vector.
static Vector	foreachColumn(Matrix matrix, RealScalarFunction f) Constructs a vector in which each entry is the result of applying a RealScalarFunction to each column of an input matrix.
static Vector	foreachRow(Matrix matrix, RealScalarFunction f) Constructs a vector in which each entry is the result of applying a RealScalarFunction to each row of an input matrix.
static Vector	foreachVector(Collection<Vector> vectors, RealScalarFunction f) Applies a RealScalarFunction on each input vector.
static Vector[]	foreachVector(Collection<Vector> vectors, RealVectorFunction f) Applies a real vector function on each input vector.
static Vector	foreachVector(Vector[] vectors, RealScalarFunction f) Applies a RealScalarFunction on each input vector.
static Vector[]	foreachVector(Vector[] vectors, RealVectorFunction f) Applies a real vector function on each input vector.
static Vector[]	get0s(int dimension, int n) Gets n 0 vectors.
static Vector	getCoordinate(Collection<Vector> vectors, int i) Gets the vector entries from a particular coordinate.
static Vector	getCoordinate(Vector[] vectors, int i) Gets the vector entries from a particular coordinate.
static List<Vector>	getOffsetVectors(Vector v0, Vector dv, int a, int b) Given the reference vector v0, the delta dv, and the range [a, b], the offset vectors are: \[ v0 + a \cdot dv, v0 + (a + 1) \cdot dv, \ldots , v0 + b \cdot dv
static Vector	replaceInPlace(Vector original, int from, Vector replacement) Replaces a sub-vector with a given smaller vector.
static Vector	subDiagonal(Matrix A) Gets the sub-diagonal of a matrix as a vector.
static SparseVector	subDiagonal(SparseMatrix A) Gets the sub-diagonal of a sparse matrix as a sparse vector.
static SparseVector	subVector(SparseVector vector, int from, int to) Gets a sub-vector from a sparse vector.
static Vector	subVector(Vector vector, int[] indices) Gets a sub-vector from a vector according to a given array of ordered indices (repetition allowed).
static Vector	subVector(Vector vector, int from, int to) Gets a sub-vector from a vector.
static Vector	subVector(Vector vector, List<Integer> indices) Gets a sub-vector from a vector according to a given array of ordered indices (repetition allowed).
static Vector	superDiagonal(Matrix A) Gets the super-diagonal of a matrix as a vector.
static SparseVector	superDiagonal(SparseMatrix A) Gets the super-diagonal of a sparse matrix as a sparse vector.

Methods inherited from class java.lang.Object

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

Method Detail

concat

public static Vector concat(Vector... vectors)

Concatenates an array of vectors into one vector.

Parameters:

vectors - an array of vectors, e.g., \((v_1, v_2, v_3, ...)\).

Returns:

\(c(v_1, v_2, v_3, ...)\)

concat

public static Vector concat(Collection<Vector> vectors)

Concatenates an array of vectors into one vector.

Parameters:

vectors - an array of vectors, e.g., \((v_1, v_2, v_3, ...)\).

Returns:

\(c(v_1, v_2, v_3, ...)\)

concat

public static SparseVector concat(SparseVector... vectors)

Concatenates an array of sparse vectors into one sparse vector.

Parameters:

vectors - an array of sparse vectors, e.g., \((v_1, v_2, v_3, ...)\).

Returns:

\(c(v_1, v_2, v_3, ...)\)

replaceInPlace

public static Vector replaceInPlace(Vector original,
                                    int from,
                                    Vector replacement)

Replaces a sub-vector with a given smaller vector.

Parameters:

original - the original vector

from - the beginning entry index to replace

replacement - the vector to be inserted to the original vector

Returns:

the modified vector

foreach

public static Vector foreach(Vector vector,
                             DoubleUnaryOperator f)

Constructs a new vector in which each entry is the result of applying a function to the corresponding entry of a vector. For example,

 
 Vector v1 = foreach(v0, x -> 2 * x); // double each entry in v0
 

Parameters:

f - the function to be applied to each entry of a vector

vector - a vector

Returns:

\([f(v_{i})]\) for all is

foreach

public static Vector foreach(Vector vector,
                             UnivariateRealFunction f)

Constructs a new vector in which each entry is the result of applying a function to the corresponding entry of a vector.

Parameters:

f - the function to be applied to each entry of a vector

vector - a vector

Returns:

\([f(v_{i})]\) for all is

foreach

public static SparseVector foreach(SparseVector vector,
                                   UnivariateRealFunction f)

Constructs a new vector in which each entry is the result of applying a function to the corresponding entry of a sparse vector. Note that this operation may not preserve sparsity.

Parameters:

f - the function to be applied to each entry of a vector

vector - a sparse vector

Returns:

\([f(v_{i})]\) for all is

subVector

public static Vector subVector(Vector vector,
                               int from,
                               int to)

Gets a sub-vector from a vector.

Parameters:

vector - a vector

from - the beginning index

to - the ending index

Returns:

v[from : to]

subVector

public static SparseVector subVector(SparseVector vector,
                                     int from,
                                     int to)

Gets a sub-vector from a sparse vector.

Parameters:

vector - a sparse vector

from - the beginning index

to - the ending index

Returns:

v[from : to]

subVector

public static Vector subVector(Vector vector,
                               List<Integer> indices)

Gets a sub-vector from a vector according to a given array of ordered indices (repetition allowed).

Parameters:

vector - a vector

indices - the list of ordered indices (repetition allowed)

Returns:

a sub-vector

subVector

public static Vector subVector(Vector vector,
                               int[] indices)

Gets a sub-vector from a vector according to a given array of ordered indices (repetition allowed).

Parameters:

vector - a vector

indices - the array of ordered indices (repetition allowed)

Returns:

a sub-vector

diagonal

public static Vector diagonal(Matrix A)

Gets the diagonal of a matrix as a vector.

Parameters:

A - a matrix

Returns:

a vector whose entries are \(A_{i}\)

diagonal

public static SparseVector diagonal(SparseMatrix A)

Gets the diagonal of a sparse matrix as a sparse vector.

Parameters:

A - a sparse matrix

Returns:

a sparse vector whose entries are \(A_{i}\)

superDiagonal

public static Vector superDiagonal(Matrix A)

Gets the super-diagonal of a matrix as a vector.

Parameters:

A - a matrix

Returns:

a vector whose entries are \(A_{i,i+1}\)

superDiagonal

public static SparseVector superDiagonal(SparseMatrix A)

Gets the super-diagonal of a sparse matrix as a sparse vector.

Parameters:

A - a sparse matrix

Returns:

a sparse vector whose entries are \(A_{i,i+1}\)

subDiagonal

public static Vector subDiagonal(Matrix A)

Gets the sub-diagonal of a matrix as a vector.

Parameters:

A - a matrix

Returns:

a vector whose entries are \(A_{i+1,i}\)

subDiagonal

public static SparseVector subDiagonal(SparseMatrix A)

Gets the sub-diagonal of a sparse matrix as a sparse vector.

Parameters:

A - a sparse matrix

Returns:

a sparse vector whose entries are \(A_{i+1,i}\)

foreachRow

public static Vector foreachRow(Matrix matrix,
                                RealScalarFunction f)

Constructs a vector in which each entry is the result of applying a RealScalarFunction to each row of an input matrix.

Parameters:

matrix - the input matrix

f - the real scalar function

Returns:

the vector containing the results

foreachColumn

public static Vector foreachColumn(Matrix matrix,
                                   RealScalarFunction f)

Constructs a vector in which each entry is the result of applying a RealScalarFunction to each column of an input matrix.

Parameters:

matrix - the input matrix

f - the real scalar function

Returns:

the vector containing the results

foreachVector

public static Vector foreachVector(Vector[] vectors,
                                   RealScalarFunction f)

Applies a RealScalarFunction on each input vector.

Parameters:

vectors - the input vectors

f - the real scalar function

Returns:

the values after applying f on the vectors

foreachVector

public static Vector foreachVector(Collection<Vector> vectors,
                                   RealScalarFunction f)

Applies a RealScalarFunction on each input vector.

Parameters:

vectors - the input vectors

f - the real scalar function

Returns:

the values after applying f on the vectors

foreachVector

public static Vector[] foreachVector(Vector[] vectors,
                                     RealVectorFunction f)

Applies a real vector function on each input vector.

Parameters:

vectors - the input vectors

f - the real vector function

Returns:

the output vectors after applying the function

foreachVector

public static Vector[] foreachVector(Collection<Vector> vectors,
                                     RealVectorFunction f)

Applies a real vector function on each input vector.

Parameters:

vectors - the input vectors

f - the real vector function

Returns:

the output vectors after applying the function

getCoordinate

public static Vector getCoordinate(Vector[] vectors,
                                   int i)

Gets the vector entries from a particular coordinate. If all input vectors are sparse, then returns a sparse vector.

Parameters:

vectors - the input vectors

i - the index to a vector entry; the coordinate index

Returns:

a vector composed of the entries from a particular coordinate

getCoordinate

public static Vector getCoordinate(Collection<Vector> vectors,
                                   int i)

Gets the vector entries from a particular coordinate.

Parameters:

vectors - the input vectors

i - the index to a vector entry; the coordinate index

Returns:

a vector composed of the entries from a particular coordinate

getOffsetVectors

public static List<Vector> getOffsetVectors(Vector v0,
                                            Vector dv,
                                            int a,
                                            int b)

Given the reference vector v0, the delta dv, and the range [a, b], the offset vectors are: \[ v0 + a \cdot dv, v0 + (a + 1) \cdot dv, \ldots , v0 + b \cdot dv. \]

Parameters:

v0 - the reference vector v0

dv - the change (base offset) made to the vector at each step dv

a - the minimum multiple of dv that is added to v0

b - the maximum multiple of dv that is added to v0

Returns:

a list containing the vector

cumsum

public static Vector[] cumsum(Vector[] arr)

Gets the cumulative sums.

Parameters:

arr - an array of vectors

Returns:

the cumulative sum, element-by-element

get0s

public static Vector[] get0s(int dimension,
                             int n)

Gets n 0 vectors.

Parameters:

dimension - the dimension of the vectors

n - the number of 0 vectors

Returns:

n 0 vectors