Class Matrix

Object
   |
   +--Matrix

class Matrix

Defined in Matrix.js

Requires:

- Vector

Field Detail

components

Array components

an Array whose elements are Vectors, the vectors being rows of the matrix

Matrix

Matrix(<Object> elements)

Constructor function. Note that a Matrix object is an Array, where each component is a Vector, representing a row of the matrix.

Parameters:
elements - The elements of the new matrix. Can either be an Array (one-dimensional, multi-dimensional, or an Array of Vector objects) or a Matrix (in which case it will be cloned into a new one).

Requires:
- Vector

add

Matrix add(<Matrix> matrix)

Adds a matrix to another one of the same size.

Parameters:
matrix - the matrix to be added to the original one

Returns:
a new matrix that is the sum of the two or null if not same size

augment

Matrix augment(<Matrix> matrix)

Augments a matrix to the right of a matrix.

Parameters:
matrix - the matrix to augment

Returns:
a new matrix that is the augmentation of the two (or the original matrix if the supplied matrix has a different number of rows)

canMultiplyFromLeft

Boolean canMultiplyFromLeft(<Object> matrix)

Tests to see whether the supplied matrix can be multiplied by this matrix in Matrix.prototype.form = this;times matrix.

Parameters:
matrix - Matrix, Vector, or scalar to be tested

Returns:
true if matrix/vector can be multiplied from left or if matrix is a number; false otherwise

col

Vector col(<Integer> j)

Returns the j'th column as a vector.

Parameters:
j - the number of the column you want

Returns:
the j'th column as a vector

det

Object det()

Shorthand for determinant()

See:
- determinant()

determinant

Number determinant()

Calculates the determinant of a square matrix (returns null if matrix not a square).

Returns:
the determinant

dimensions

Object dimensions()

Returns the dimensions of the matrix as an Object. Called as thisMatrix.dimensions().rows or .columns (see sameSize method).

Returns:
a new object with the two values rows = numRows, columns = numCols

equalTo

Boolean equalTo(<Matrix> matrix)

Checks two matrices for equality.

Parameters:
matrix - the matrix to compare to the original

Returns:
true iff both are equal, false otherwise

get

Number get(<Integer> i,<Integer> j)

Returns the i,j'th element of the matrix. Becaues (i,j) element is this.components[i-1].components[j-1], this method is especially uesful as shorthand.

Parameters:
i - the row number of the element
j - the column number of the element

Returns:
the element at i,j

getDiagonal

Vector getDiagonal()

Gets and returns the diagonal entries of a square matrix.

Returns:
a new vector that is the diagonal elements of the matrix

indexOf

Object indexOf(<Number> val)

Returns the indices of the FIRST occurence of a given value.

Parameters:
val - the component for which to find the indices

Returns:
an object with properties i = row, j = column; if you want the row of the first occurence of val, matrix.indexOf(val).i

invert

Matrix invert()

Inverts an invertible matrix and returns the inverse.

Returns:
a new matrix that is the inverse of the original (null if original not invertible)

invertible

Boolean invertible()

Tests to see if a matrix is or is not invertible.

Returns:
true iff matrix is invertible, false if not

isSingular

Boolean isSingular()

Tests a matrix for singularity.

Returns:
true iff matrix is singular (square and invertible), false otherwise

isSquare

Boolean isSquare()

Tests to see if a matrix is square or not.

Returns:
true if matrix is a square, false otherwise

map

Matrix map(<Function> func)

Maps a matrix onto a new one according to a supplied function.

Parameters:
func - the mapping function

Returns:
the new, mapped matrix

max

Number max()

Returns the absolute maximum component of the matrix.

Returns:
the value of the component with the largest absolute value

minor

Matrix minor(<Integer> row, <Integer> col, <Integer> numrows, <Integer> numcols)

Creates a sub-matrix from the original matrix. Element selection wraps, so this method can be used to do row or column cycling and copy augmenting

Parameters:
row - the row to start at
col - the column to start at
numrows - the number of rows for the submatrix
numcols - the number of columns

Returns:
a new matrix that is the minor matrix from rows row to row+numrows and col to col+numcols

multiply

Object multiply(<Object> matrix)

If possible, multiplies the supplied matrix by this matrix.

Parameters:
matrix - the matrix, vector, or number (will do scalar multiplication) to be multiplied

Returns:
new matrix that is the matrix product if matrix is Vector or Number; new Vector if matrix is a vector

multiplyBy

Matrix multiplyBy(<Number> k)

Multiplies a matrix by a scalar value.

Parameters:
k - the scalar by which to multiply the matrix

Returns:
a new matrix that is the scalar multiple of the original

negative

Matrix negative()

Returns the negative version of the current matrix.

Returns:
a new, negative copy of the original matrix.

numCols

Integer numCols()

Get the number of columns in the matrix.

Returns:
the number of columns

numRows

Integer numRows()

Get the number of rows in the matrix.

Returns:
the number of rows

rank

Number rank()

Calculates the rank of a matrix.

Returns:
the rank (calculated without complete row reduction)

round

Matrix round()

Rounds all the elements of a matrix into a new one.

Returns:
the new matrix that is the rounded version of the original

row

Vector row(<Integer> i)

Returns a specific row of the matrix as a Vector (which it is already)

Parameters:
i - the row you want

Returns:
the i'th row of the matrix;

sameSizeAs

Boolean sameSizeAs(<Matrix> matrix)

Tests to see if two matrices are the same size.

Parameters:
matrix - the matrix with which size is to be compared

Returns:
true iff same size, false otherwise

setElement

void setElement(<Integer> i, <Integer> j, <Number> val)

Sets the i,j'th element to val. Matrix.prototype.Note = this;modifies current matrix, does not return a new one.

Parameters:
i - the row of the element to set
j - the column of the element to set
val - the value to set element (i,j) to

snapTo

Object snapTo(<Number> val)

Sets all values within range of Zero (set in easyload.js) to val.

Parameters:
val - the number to snap the matrix to

subtract

Matrix subtract(<Matrix> matrix)

Subtracts another matrix of the same size from this one.

Parameters:
matrix - the matrix to be subtracted the original one

Returns:
a new matrix that is the difference of the two or null if not same size

toString

String toString()

Creates and returns a string representation of the matrix.

Returns:
the string representation of the matrix

toUpperTriangular

Matrix toUpperTriangular()

Uses a modified version of Gaussian elimination to create and return a new, upper triangular version of the original matrix while preserving determinant and rank.

Returns:
the upper triangular version of the matrix as a new matrix object

toVector

Vector toVector()

Makes a Vector out of a 1-D (row or column) Matrix.

Returns:
the new Vector, or null if Matrix cannot become a Vector.

tr

Object tr()

Shorthand for trace() function.

See:
- trace()

trace

Number trace()

Computes the trace of a square matrix (returns null if matrix is not a square).

Returns:
the trace (sum of diagonal elements) of the matrix

transpose

Matrix transpose()

Creates a new matrix that is the transpose of the original matrix.

Returns:
the transpose of the original matrix, as a new matrix

diagonal

<static> Object diagonal(<Object> elements)

Creates a diagonal matrix (off-diagonal elements are 0) from a given array of elements

Parameters:
elements - either a Vector or 1-D array that will become the diagonal elements of a matrix that has elements.length rows and columns

I

<static> Matrix I(<Integer> n)

Creates the Identity matrix of dimension N.

Parameters:
n - the size of the identity matrix to be created

Returns:
an identity matrix of size n x n

random

<static> Object random(<Integer> rows, <Integer> cols, <Integer> max)

Creates a rows x cols matrix with random elements between 0 and max

Parameters:
rows - the number of rows
cols - the number of columns
max - (Optional) - the maximum value (included) that any element can have; if supplied, all elements will be integers

zero

<static> Matrix zero(<Integer> rows, <Integer> cols)

Creates a rows x cols matrix with all 0 elements.

Parameters:
rows - the number of rows for the 0 matrix
cols - the number of columns

Returns:
a rows x cols 0 matrix