DoubleMatrix (jblas 1.2.4 API)

java.lang.Object
- org.jblas.DoubleMatrix

All Implemented Interfaces:: Serializable

public class DoubleMatrix
extends Object
implements Serializable

A general matrix class for double typed values. Don't be intimidated by the large number of methods this function defines. Most are overloads provided for ease of use. For example, for each arithmetic operation, up to six overloaded versions exist to handle in-place computations, and scalar arguments (like adding a number to all elements of a matrix).

Construction

To construct a two-dimensional matrices, you can use the following constructors and static methods.

Method	Description
DoubleMatrix(m,n, [value1, value2, value3...])	Values are filled in column by column.
DoubleMatrix(new double[][] {{value1, value2, ...}, ...}	Inner arrays are rows.
DoubleMatrix.zeros(m,n)	Initial values set to 0.0.
DoubleMatrix.ones(m,n)	Initial values set to 1.0.
DoubleMatrix.rand(m,n)	Values drawn at random between 0.0 and 1.0.
DoubleMatrix.randn(m,n)	Values drawn from normal distribution.
DoubleMatrix.eye(n)	Unit matrix (values 0.0 except for 1.0 on the diagonal).
DoubleMatrix.diag(array)	Diagonal matrix with given diagonal elements.

Alternatively, you can construct (column) vectors, if you just supply the length using the following constructors and static methods.

Method	Description
DoubleMatrix(m)	Constructs a column vector.
DoubleMatrix(new double[] {value1, value2, ...})	Constructs a column vector.
DoubleMatrix.zeros(m)	Initial values set to 0.0.
DoubleMatrix.ones(m)	Initial values set to 1.0.
DoubleMatrix.rand(m)	Values drawn at random between 0.0 and 1.0.
DoubleMatrix.randn(m)	Values drawn from normal distribution.
DoubleMatrix.linspace(a, b, n)	n linearly spaced values from a to b.
DoubleMatrix.logspace(a, b, n)	n logarithmically spaced values form 10^a to 10^b.

You can also construct new matrices by concatenating matrices either horziontally or vertically:

Method	Description
x.concatHorizontally(y)	New matrix will be x next to y.
x.concatVertically(y)	New matrix will be x atop y.

Element Access, Copying and Duplication

To access individual elements, or whole rows and columns, use the following methods:

x.Method	Description
x.get(i,j)	Get element in row i and column j.
x.put(i, j, v)	Set element in row i and column j to value v
x.get(i)	Get the ith element of the matrix (traversing rows first).
x.put(i, v)	Set the ith element of the matrix (traversing rows first).
x.getColumn(i)	Get a copy of column i.
x.putColumn(i, c)	Put matrix c into column i.
x.getRow(i)	Get a copy of row i.
x.putRow(i, c)	Put matrix c into row i.
x.swapColumns(i, j)	Swap the contents of columns i and j.
x.swapRows(i, j)	Swap the contents of rows i and j.

For get and put, you can also pass integer arrays, DoubleMatrix objects, or Range objects, which then specify the indices used as follows:

integer array: the elements will be used as indices.
DoubleMatrix object: non-zero entries specify the indices.
Range object: see below.

When using put with multiple indices, the assigned object must have the correct size or be a scalar.

There exist the following Range objects. The Class RangeUtils also contains the a number of handy helper methods for constructing these ranges.

Class	RangeUtils method	Indices
AllRange	all()	All legal indices.
PointRange	point(i)	A single point.
IntervalRange	interval(a, b)	All indices from a to b (inclusive)
IndicesRange	indices(int[])	The specified indices.
	indices(DoubleMatrix)	The specified indices.
	find(DoubleMatrix)	The non-zero entries of the matrix.

The following methods can be used for duplicating and copying matrices.

Method	Description
x.dup()	Get a copy of x.
x.copy(y)	Copy the contents of y to x (possible resizing x).

Size and Shape

The following methods permit to access the size of a matrix and change its size or shape.

x.Method	Description
x.rows	Number of rows.
x.columns	Number of columns.
x.length	Total number of elements.
x.isEmpty()	Checks whether rows == 0 and columns == 0.
x.isRowVector()	Checks whether rows == 1.
x.isColumnVector()	Checks whether columns == 1.
x.isVector()	Checks whether rows == 1 or columns == 1.
x.isSquare()	Checks whether rows == columns.
x.isScalar()	Checks whether length == 1.
x.resize(r, c)	Resize the matrix to r rows and c columns, discarding the content.
x.reshape(r, c)	Resize the matrix to r rows and c columns. Number of elements must not change.

The size is stored in the rows and columns member variables. The total number of elements is stored in length. Do not change these values unless you know what you're doing!

Arithmetics

The usual arithmetic operations are implemented. Each operation exists in a in-place version, recognizable by the suffix "i", to which you can supply the result matrix (or this is used, if missing). Using in-place operations can also lead to a smaller memory footprint, as the number of temporary objects is reduced (although the JVM garbage collector is usually pretty good at reusing these temporary object immediately with little overhead.)

Whenever you specify a result vector, the result vector must already have the correct dimensions.

For example, you can add two matrices using the add method. If you want to store the result in of x + y in z, type x.addi(y, z) // computes x = y + z. Even in-place methods return the result, such that you can easily chain in-place methods, for example: x.addi(y).addi(z) // computes x += y; x += z

Methods which operate element-wise only make sure that the length of the matrices is correct. Therefore, you can add a 3 * 3 matrix to a 1 * 9 matrix, for example.

Finally, there exist versions which take doubles instead of DoubleMatrix Objects as arguments. These then compute the operation with the same value as the right-hand-side. The same effect can be achieved by passing a DoubleMatrix with exactly one element.

Operation	Method	Comment
x + y	x.add(y)
x - y	x.sub(y), y.rsub(x)	rsub subtracts left from right hand side
x * y	x.mul(y)	element-wise multiplication
	x.mmul(y)	matrix-matrix multiplication
	x.dot(y)	scalar-product
x / y	x.div(y), y.rdiv(x)	rdiv divides right hand side by left hand side.
- x	x.neg()

There also exist operations which work on whole columns or rows.

Method	Description
x.addRowVector	adds a vector to each row (addiRowVector works in-place)
x.addColumnVector	adds a vector to each column
x.subRowVector	subtracts a vector from each row
x.subColumnVector	subtracts a vector from each column
x.mulRowVector	Multiplies each row by a vector (elementwise)
x.mulColumnVector	Multiplies each column by a vector (elementwise)
x.divRowVector	Divide each row by a vector (elementwise)
x.divColumnVector	Divide each column by a vector (elementwise)
x.mulRow	Multiplies a row by a scalar
x.mulColumn	Multiplies a column by a scalar

In principle, you could achieve the same result by first calling getColumn(), adding, and then calling putColumn, but these methods are much faster.

The following comparison operations are available

Operation	Method
x < y	x.lt(y)
x <= y	x.le(y)
x > y	x.gt(y)
x >= y	x.ge(y)
x == y	x.eq(y)
x != y	x.ne(y)

Logical operations are also supported. For these operations, a value different from zero is treated as "true" and zero is treated as "false". All operations are carried out elementwise.

Operation	Method
x & y	x.and(y)
x \| y	x.or(y)
x ^ y	x.xor(y)
! x	x.not()

Finally, there are a few more methods to compute various things:

Method	Description
x.max()	Return maximal element
x.argmax()	Return index of largest element
x.min()	Return minimal element
x.argmin()	Return index of largest element
x.columnMins()	Return column-wise minima
x.columnArgmins()	Return column-wise index of minima
x.columnMaxs()	Return column-wise maxima
x.columnArgmaxs()	Return column-wise index of maxima

Author:: Mikio Braun, Johannes Schaback
See Also:: Serialized Form

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`class`	`DoubleMatrix.ColumnsAsListView`
`class`	`DoubleMatrix.ElementsAsListView` A wrapper which allows to view a matrix as a List of Doubles (read-only!).
`class`	`DoubleMatrix.RowsAsListView`

Field Summary

Fields
Modifier and Type	Field and Description
`int`	`columns` Number of columns.
`double[]`	`data` The actual data stored by rows (that is, row 0, row 1...).
`static DoubleMatrix`	`EMPTY`
`int`	`length` Total number of elements (for convenience).
`int`	`rows` Number of rows.

Constructor Summary

Constructors
Constructor and Description
`DoubleMatrix()` Creates a new `DoubleMatrix` of size 0 times 0.
`DoubleMatrix(double[] newData)` Create a a column vector using newData as the data array.
`DoubleMatrix(double[][] data)` Creates a new n times m `DoubleMatrix` from the given n times m 2D data array.
`DoubleMatrix(int len)` Create a Matrix of length `len`.
`DoubleMatrix(int newRows, int newColumns)` Creates a new n times m `DoubleMatrix`.
`DoubleMatrix(int newRows, int newColumns, double... newData)` Create a new matrix with newRows rows, newColumns columns using newData> as the data.
`DoubleMatrix(List<Double> data)` Creates a DoubleMatrix column vector from the given List<Double&rt;.
`DoubleMatrix(String filename)` Creates a new matrix by reading it from a file.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`DoubleMatrix`	`add(double v)` Add a scalar.
`DoubleMatrix`	`add(DoubleMatrix other)` Add a matrix.
`DoubleMatrix`	`addColumnVector(DoubleMatrix x)` Add a vector to all columns of the matrix.
`DoubleMatrix`	`addi(double v)` Add a scalar (in place).
`DoubleMatrix`	`addi(double v, DoubleMatrix result)` Add a scalar to a matrix (in-place).
`DoubleMatrix`	`addi(DoubleMatrix other)` Add a matrix (in place).
`DoubleMatrix`	`addi(DoubleMatrix other, DoubleMatrix result)` Add two matrices (in-place).
`DoubleMatrix`	`addiColumnVector(DoubleMatrix x)` Add a vector to all columns of the matrix (in-place).
`DoubleMatrix`	`addiRowVector(DoubleMatrix x)` Add a row vector to all rows of the matrix (in place).
`DoubleMatrix`	`addRowVector(DoubleMatrix x)` Add a row to all rows of the matrix.
`DoubleMatrix`	`and(double value)` Compute elementwise logical and against a scalar.
`DoubleMatrix`	`and(DoubleMatrix other)` Compute elementwise logical and.
`DoubleMatrix`	`andi(double value)` Compute elementwise logical and against a scalar (in-place).
`DoubleMatrix`	`andi(double value, DoubleMatrix result)` Compute elementwise logical and against a scalar (in-place).
`DoubleMatrix`	`andi(DoubleMatrix other)` Compute elementwise logical and (in-place).
`DoubleMatrix`	`andi(DoubleMatrix other, DoubleMatrix result)` Compute elementwise logical and (in-place).
`int`	`argmax()` Returns the linear index of the maximal element of the matrix.
`int`	`argmin()` Returns the linear index of the minimal element.
`void`	`assertMultipliesWith(DoubleMatrix a)` Throws SizeException unless matrices can be multiplied with one another.
`void`	`assertSameLength(DoubleMatrix a)` Throws SizeException unless matrices have the same length.
`void`	`assertSameSize(DoubleMatrix a)` Throws SizeException unless two matrices have the same size.
`void`	`assertSquare()` Throw SizeException unless matrix is square.
`void`	`checkColumns(int c)` Asserts that the amtrix has a certain number of columns.
`void`	`checkLength(int l)` Assert that the matrix has a certain length.
`void`	`checkRows(int r)` Asserts that the matrix has a certain number of rows.
`int[]`	`columnArgmaxs()` Return index of minimal element per column.
`int[]`	`columnArgmins()` Return index of minimal element per column.
`DoubleMatrix`	`columnMaxs()` Return column-wise maximums.
`DoubleMatrix`	`columnMeans()` Return a vector containing the means of all columns.
`DoubleMatrix`	`columnMins()` Return column-wise minimums.
`List<DoubleMatrix>`	`columnsAsList()`
`int[][]`	`columnSortingPermutations()` Return matrix of indices which sort all columns.
`DoubleMatrix`	`columnSums()` Return a vector containing the sums of the columns (having number of columns many entries)
`boolean`	`compare(Object o, double tolerance)` Compare two matrices.
`static DoubleMatrix`	`concatHorizontally(DoubleMatrix A, DoubleMatrix B)` Concatenates two matrices horizontally.
`static DoubleMatrix`	`concatVertically(DoubleMatrix A, DoubleMatrix B)` Concatenates two matrices vertically.
`DoubleMatrix`	`copy(DoubleMatrix a)` Copy DoubleMatrix a to this.
`DoubleMatrix`	`cumulativeSum()` Computes the cumulative sum, that is, the sum of all elements of the matrix up to a given index in linear addressing.
`DoubleMatrix`	`cumulativeSumi()` Computes the cumulative sum, that is, the sum of all elements of the matrix up to a given index in linear addressing (in-place).
`DoubleMatrix`	`diag()` Returns the diagonal of the matrix.
`static DoubleMatrix`	`diag(DoubleMatrix x)` Creates a new matrix where the values of the given vector are the diagonal values of the matrix.
`static DoubleMatrix`	`diag(DoubleMatrix x, int rows, int columns)` Construct a matrix of arbitrary shape and set the diagonal according to a passed vector.
`double`	`distance1(DoubleMatrix other)` Returns the (1-norm) distance.
`double`	`distance2(DoubleMatrix other)` Returns the (euclidean) distance.
`DoubleMatrix`	`div(double v)` Elementwise divide by a scalar.
`DoubleMatrix`	`div(DoubleMatrix other)` Elementwise divide by a matrix.
`DoubleMatrix`	`divColumnVector(DoubleMatrix x)`
`DoubleMatrix`	`divi(double v)` Elementwise divide by a scalar (in place).
`DoubleMatrix`	`divi(double a, DoubleMatrix result)` Elementwise division with a scalar (in-place).
`DoubleMatrix`	`divi(DoubleMatrix other)` Elementwise divide by a matrix (in place).
`DoubleMatrix`	`divi(DoubleMatrix other, DoubleMatrix result)` Elementwise division (in-place).
`DoubleMatrix`	`diviColumnVector(DoubleMatrix x)`
`DoubleMatrix`	`diviRowVector(DoubleMatrix x)`
`DoubleMatrix`	`divRowVector(DoubleMatrix x)`
`double`	`dot(DoubleMatrix other)` The scalar product of this with other.
`DoubleMatrix`	`dup()` Returns a duplicate of this matrix.
`List<Double>`	`elementsAsList()`
`DoubleMatrix`	`eq(double value)` test for equality against a scalar.
`DoubleMatrix`	`eq(DoubleMatrix other)` Test for equality.
`DoubleMatrix`	`eqi(double value)` Test for equality against a scalar (in-place).
`DoubleMatrix`	`eqi(double value, DoubleMatrix result)` Test for equality against a scalar (in-place).
`DoubleMatrix`	`eqi(DoubleMatrix other)` Test for equality (in-place).
`DoubleMatrix`	`eqi(DoubleMatrix other, DoubleMatrix result)` Test for equality (in-place).
`boolean`	`equals(Object o)`
`static DoubleMatrix`	`eye(int n)` Construct a new n-by-n identity matrix.
`DoubleMatrix`	`fill(double value)` Set all elements to a value.
`int[]`	`findIndices()` Find the linear indices of all non-zero elements.
`DoubleMatrix`	`ge(double value)` test for "greater than or equal" against a scalar.
`DoubleMatrix`	`ge(DoubleMatrix other)` Test for "greater than or equal".
`DoubleMatrix`	`gei(double value)` Test for "greater than or equal" against a scalar (in-place).
`DoubleMatrix`	`gei(double value, DoubleMatrix result)` Test for "greater than or equal" against a scalar (in-place).
`DoubleMatrix`	`gei(DoubleMatrix other)` Test for "greater than or equal" (in-place).
`DoubleMatrix`	`gei(DoubleMatrix other, DoubleMatrix result)` Test for "greater than or equal" (in-place).
`DoubleMatrix`	`get(DoubleMatrix indices)` Get elements specified by the non-zero entries of the passed matrix.
`DoubleMatrix`	`get(DoubleMatrix rindices, DoubleMatrix cindices)` Get elements from columns and rows as specified by the non-zero entries of the passed matrices.
`DoubleMatrix`	`get(DoubleMatrix indices, int c)` Get elements from a column and rows as specified by the non-zero entries of a matrix.
`double`	`get(int i)` Get a matrix element (linear indexing).
`DoubleMatrix`	`get(int[] indices)` Get all elements specified by the linear indices.
`DoubleMatrix`	`get(int[] indices, int c)` Get all elements for a given column and the specified rows.
`DoubleMatrix`	`get(int[] rindices, int[] cindices)` Get all elements from the specified rows and columns.
`DoubleMatrix`	`get(int r, DoubleMatrix indices)` Get elements from a row and columns as specified by the non-zero entries of a matrix.
`double`	`get(int rowIndex, int columnIndex)` Retrieve matrix element
`DoubleMatrix`	`get(int r, int[] indices)` Get all elements for a given row and the specified columns.
`DoubleMatrix`	`get(int r, Range cs)`
`DoubleMatrix`	`get(Range rs, int c)`
`DoubleMatrix`	`get(Range rs, Range cs)` Get elements from specified rows and columns.
`DoubleMatrix`	`getColumn(int c)` Get a copy of a column.
`DoubleMatrix`	`getColumn(int c, DoubleMatrix result)` Copy a column to the given vector.
`DoubleMatrix`	`getColumnRange(int r, int a, int b)` Get elements from a row and columns `a` to `b`.
`int`	`getColumns()` Get number of columns.
`DoubleMatrix`	`getColumns(DoubleMatrix cindices)` Get whole columns as specified by the non-zero entries of a matrix.
`DoubleMatrix`	`getColumns(int[] cindices)` Get whole columns from the passed indices.
`DoubleMatrix`	`getColumns(Range indices)`
`DoubleMatrix`	`getColumns(Range indices, DoubleMatrix result)` Get whole columns as specified by Range.
`int`	`getLength()` Get total number of elements.
`DoubleMatrix`	`getRange(int a, int b)` Return all elements with linear index a, a + 1, ..., b - 1.
`DoubleMatrix`	`getRange(int ra, int rb, int ca, int cb)` Get elements from rows `ra` to `rb` and columns `ca` to `cb`.
`DoubleMatrix`	`getRow(int r)` Get a copy of a row.
`DoubleMatrix`	`getRow(int r, DoubleMatrix result)` Copy a row to a given vector.
`DoubleMatrix`	`getRowRange(int a, int b, int c)` Get elements from a column and rows `a/tt> to b.`
`int`	`getRows()` Get number of rows.
`DoubleMatrix`	`getRows(DoubleMatrix rindices)` Get whole rows as specified by the non-zero entries of a matrix.
`DoubleMatrix`	`getRows(int[] rindices)` Get whole rows from the passed indices.
`DoubleMatrix`	`getRows(Range indices)`
`DoubleMatrix`	`getRows(Range indices, DoubleMatrix result)`
`DoubleMatrix`	`gt(double value)` test for "greater than" against a scalar.
`DoubleMatrix`	`gt(DoubleMatrix other)` Test for "greater than".
`DoubleMatrix`	`gti(double value)` Test for "greater than" against a scalar (in-place).
`DoubleMatrix`	`gti(double value, DoubleMatrix result)` Test for "greater than" against a scalar (in-place).
`DoubleMatrix`	`gti(DoubleMatrix other)` Test for "greater than" (in-place).
`DoubleMatrix`	`gti(DoubleMatrix other, DoubleMatrix result)` Test for "greater than" (in-place).
`int`	`hashCode()`
`void`	`in(DataInputStream dis)` Reads in a matrix from the given data stream.
`int`	`index(int rowIndex, int columnIndex)` Get index of an element
`int`	`indexColumns(int i)` Compute the column index of a linear index.
`int`	`indexRows(int i)` Compute the row index of a linear index.
`boolean`	`isColumnVector()` Checks whether the matrix is a column vector.
`boolean`	`isEmpty()` Checks whether the matrix is empty.
`DoubleMatrix`	`isInfinite()`
`DoubleMatrix`	`isInfinitei()`
`boolean`	`isLowerTriangular()` Checks whether all entries (i, j) with i >= j are zero.
`DoubleMatrix`	`isNaN()`
`DoubleMatrix`	`isNaNi()`
`boolean`	`isRowVector()` Checks whether the matrix is a row vector.
`boolean`	`isScalar()` Test whether a matrix is scalar.
`boolean`	`isSquare()` Checks whether the matrix is square.
`boolean`	`isUpperTriangular()` Checks whether all entries (i, j) with i <= j are zero.
`boolean`	`isVector()` Checks whether the matrix is a vector.
`DoubleMatrix`	`le(double value)` test for "less than or equal" against a scalar.
`DoubleMatrix`	`le(DoubleMatrix other)` Test for "less than or equal".
`DoubleMatrix`	`lei(double value)` Test for "less than or equal" against a scalar (in-place).
`DoubleMatrix`	`lei(double value, DoubleMatrix result)` Test for "less than or equal" against a scalar (in-place).
`DoubleMatrix`	`lei(DoubleMatrix other)` Test for "less than or equal" (in-place).
`DoubleMatrix`	`lei(DoubleMatrix other, DoubleMatrix result)` Test for "less than or equal" (in-place).
`static DoubleMatrix`	`linspace(int lower, int upper, int size)` Construct a column vector whose entries are linearly spaced points from lower to upper with size many steps.
`void`	`load(String filename)` Loads a matrix from a file into this matrix.
`static DoubleMatrix`	`loadAsciiFile(String filename)`
`static DoubleMatrix`	`loadCSVFile(String filename)`
`static DoubleMatrix`	`logspace(double lower, double upper, int size)` Construct a column vector whose entries are logarithmically spaced points from 10^lower to 10^upper using the specified number of steps
`DoubleMatrix`	`lt(double value)` test for "less than" against a scalar.
`DoubleMatrix`	`lt(DoubleMatrix other)` Test for "less than".
`DoubleMatrix`	`lti(double value)` Test for "less than" against a scalar (in-place).
`DoubleMatrix`	`lti(double value, DoubleMatrix result)` Test for "less than" against a scalar (in-place).
`DoubleMatrix`	`lti(DoubleMatrix other)` Test for "less than" (in-place).
`DoubleMatrix`	`lti(DoubleMatrix other, DoubleMatrix result)` Test for "less than" (in-place).
`double`	`max()` Returns the maximal element of the matrix.
`DoubleMatrix`	`max(double v)`
`DoubleMatrix`	`max(DoubleMatrix other)` Computes the maximum between two matrices.
`DoubleMatrix`	`maxi(double v)`
`DoubleMatrix`	`maxi(double v, DoubleMatrix result)`
`DoubleMatrix`	`maxi(DoubleMatrix other)` Computes the maximum between two matrices.
`DoubleMatrix`	`maxi(DoubleMatrix other, DoubleMatrix result)` Computes the maximum between two matrices.
`double`	`mean()` Computes the mean value of all elements in the matrix, that is, `x.sum() / x.length`.
`double`	`min()` Returns the minimal element of the matrix.
`DoubleMatrix`	`min(double v)`
`DoubleMatrix`	`min(DoubleMatrix other)` Computes the minimum between two matrices.
`DoubleMatrix`	`mini(double v)`
`DoubleMatrix`	`mini(double v, DoubleMatrix result)`
`DoubleMatrix`	`mini(DoubleMatrix other)` Computes the minimum between two matrices.
`DoubleMatrix`	`mini(DoubleMatrix other, DoubleMatrix result)` Computes the minimum between two matrices.
`DoubleMatrix`	`mmul(double v)` Matrix-multiply by a scalar.
`DoubleMatrix`	`mmul(DoubleMatrix other)` Matrix-multiply by a matrix.
`DoubleMatrix`	`mmuli(double v)` Matrix-multiply by a scalar (in place).
`DoubleMatrix`	`mmuli(double v, DoubleMatrix result)` Matrix-matrix multiplication with a scalar (for symmetry, does the same as `muli(scalar)` (in-place).
`DoubleMatrix`	`mmuli(DoubleMatrix other)` Matrix-multiply by a matrix (in place).
`DoubleMatrix`	`mmuli(DoubleMatrix other, DoubleMatrix result)` Matrix-matrix multiplication (in-place).
`DoubleMatrix`	`mul(double v)` Elementwise multiply by a scalar.
`DoubleMatrix`	`mul(DoubleMatrix other)` Elementwise multiply by a matrix.
`DoubleMatrix`	`mulColumn(int c, double scale)` Multiply a column by a scalar.
`DoubleMatrix`	`mulColumnVector(DoubleMatrix x)` Multiply all columns with a column vector.
`DoubleMatrix`	`muli(double v)` Elementwise multiply by a scalar (in place).
`DoubleMatrix`	`muli(double v, DoubleMatrix result)` Elementwise multiplication with a scalar (in-place).
`DoubleMatrix`	`muli(DoubleMatrix other)` Elementwise multiply by a matrix (in place).
`DoubleMatrix`	`muli(DoubleMatrix other, DoubleMatrix result)` Elementwise multiplication (in-place).
`DoubleMatrix`	`muliColumnVector(DoubleMatrix x)` Multiply all columns with a column vector (in-place).
`DoubleMatrix`	`muliRowVector(DoubleMatrix x)` Multiply all rows with a row vector (in-place).
`DoubleMatrix`	`mulRow(int r, double scale)` Multiply a row by a scalar.
`DoubleMatrix`	`mulRowVector(DoubleMatrix x)` Multiply all rows with a row vector.
`boolean`	`multipliesWith(DoubleMatrix a)` Checks whether two matrices can be multiplied (that is, number of columns of this must equal number of rows of a.
`DoubleMatrix`	`ne(double value)` test for inequality against a scalar.
`DoubleMatrix`	`ne(DoubleMatrix other)` Test for inequality.
`DoubleMatrix`	`neg()` Negate each element.
`DoubleMatrix`	`negi()` Negate each element (in-place).
`DoubleMatrix`	`nei(double value)` Test for inequality against a scalar (in-place).
`DoubleMatrix`	`nei(double value, DoubleMatrix result)` Test for inequality against a scalar (in-place).
`DoubleMatrix`	`nei(DoubleMatrix other)` Test for inequality (in-place).
`DoubleMatrix`	`nei(DoubleMatrix other, DoubleMatrix result)` Test for inequality (in-place).
`double`	`norm1()` The 1-norm of the matrix as vector (sum of absolute values of elements).
`double`	`norm2()` The Euclidean norm of the matrix as vector, also the Frobenius norm of the matrix.
`double`	`normmax()` The maximum norm of the matrix (maximal absolute value of the elements).
`DoubleMatrix`	`not()` Maps zero to 1.0 and all non-zero values to 0.0.
`DoubleMatrix`	`noti()` Maps zero to 1.0 and all non-zero values to 0.0 (in-place).
`static DoubleMatrix`	`ones(int length)` Creates a column vector with all elements equal to 1.
`static DoubleMatrix`	`ones(int rows, int columns)` Creates a new matrix in which all values are equal 1.
`DoubleMatrix`	`or(double value)` Compute elementwise logical or against a scalar.
`DoubleMatrix`	`or(DoubleMatrix other)` Compute elementwise logical or.
`DoubleMatrix`	`ori(double value)` Compute elementwise logical or against a scalar (in-place).
`DoubleMatrix`	`ori(double value, DoubleMatrix result)` Compute elementwise logical or against a scalar (in-place).
`DoubleMatrix`	`ori(DoubleMatrix other)` Compute elementwise logical or (in-place).
`DoubleMatrix`	`ori(DoubleMatrix other, DoubleMatrix result)` Compute elementwise logical or (in-place).
`void`	`out(DataOutputStream dos)` Writes out this matrix to the given data stream.
`void`	`print()` Pretty-print this matrix to `System.out`.
`double`	`prod()` Computes the product of all elements of the matrix
`double`	`project(DoubleMatrix other)` Computes the projection coefficient of other on this.
`DoubleMatrix`	`put(DoubleMatrix indices, double v)` Put a single value into the elements specified by the non-zero entries of `indices` (linear adressing).
`DoubleMatrix`	`put(DoubleMatrix indices, DoubleMatrix v)` Put a sub-matrix into the indices specified by the non-zero entries of `indices` (linear adressing).
`DoubleMatrix`	`put(DoubleMatrix rindices, DoubleMatrix cindices, double v)` Put a single value in the specified rows and columns (non-zero entries of `rindices` and `cindices`.
`DoubleMatrix`	`put(DoubleMatrix rindices, DoubleMatrix cindices, DoubleMatrix v)` Put a sub-matrix into the specified rows and columns (non-zero entries of `rindices` and `cindices`.
`DoubleMatrix`	`put(DoubleMatrix indices, int c, double v)` Put a single value into the specified rows (non-zero entries of `indices`) of a column.
`DoubleMatrix`	`put(DoubleMatrix indices, int c, DoubleMatrix v)` Put a sub-vector into the specified rows (non-zero entries of `indices`) of a column.
`DoubleMatrix`	`put(int[] indices, double v)` Put a single value into the specified indices (linear adressing).
`DoubleMatrix`	`put(int[] indices, DoubleMatrix x)` Set elements in linear ordering in the specified indices.
`DoubleMatrix`	`put(int[] rindices, int[] cindices, double v)` Put a single value into the specified rows and columns.
`DoubleMatrix`	`put(int[] rindices, int[] cindices, DoubleMatrix x)` Put a sub-matrix as specified by the indices.
`DoubleMatrix`	`put(int[] indices, int c, double v)` Put a single value into the specified rows of a column.
`DoubleMatrix`	`put(int[] indices, int c, DoubleMatrix x)` Set multiple elements in a row.
`DoubleMatrix`	`put(int i, double v)` Set a matrix element (linear indexing).
`DoubleMatrix`	`put(int r, DoubleMatrix indices, double v)` Put a single value into the specified columns (non-zero entries of `indices`) of a row.
`DoubleMatrix`	`put(int r, DoubleMatrix indices, DoubleMatrix v)` Put a sub-vector into the specified columns (non-zero entries of `indices`) of a row.
`DoubleMatrix`	`put(int r, int[] indices, double v)` Put a single value into a row and the specified columns.
`DoubleMatrix`	`put(int r, int[] indices, DoubleMatrix x)` Set multiple elements in a row.
`DoubleMatrix`	`put(int rowIndex, int columnIndex, double value)` Set matrix element
`DoubleMatrix`	`put(Range rs, Range cs, DoubleMatrix x)` Put a matrix into specified indices.
`void`	`putColumn(int c, DoubleMatrix v)` Copy a column back into the matrix.
`void`	`putRow(int r, DoubleMatrix v)` Copy a row back into the matrix.
`static DoubleMatrix`	`rand(int len)` Creates a column vector with random values uniformly in 0..1.
`static DoubleMatrix`	`rand(int rows, int columns)` Create matrix with random values uniformly in 0..1.
`static DoubleMatrix`	`randn(int len)` Create column vector with normally distributed random values.
`static DoubleMatrix`	`randn(int rows, int columns)` Create matrix with normally distributed random values.
`DoubleMatrix`	`rankOneUpdate(double alpha, DoubleMatrix x)` Computes a rank-1-update A = A + alpha * x * x'.
`DoubleMatrix`	`rankOneUpdate(double alpha, DoubleMatrix x, DoubleMatrix y)` Computes a rank-1-update A = A + alpha * x * y'.
`DoubleMatrix`	`rankOneUpdate(DoubleMatrix x)` Computes a rank-1-update A = A + x * x'.
`DoubleMatrix`	`rankOneUpdate(DoubleMatrix x, DoubleMatrix y)` Computes a rank-1-update A = A + x * y'.
`DoubleMatrix`	`rdiv(double v)` (right-)elementwise divide by a scalar.
`DoubleMatrix`	`rdiv(DoubleMatrix other)` (right-)elementwise divide by a matrix.
`DoubleMatrix`	`rdivi(double v)` (right-)elementwise divide by a scalar (in place).
`DoubleMatrix`	`rdivi(double a, DoubleMatrix result)` (Elementwise) division with a scalar, with operands switched.
`DoubleMatrix`	`rdivi(DoubleMatrix other)` (right-)elementwise divide by a matrix (in place).
`DoubleMatrix`	`rdivi(DoubleMatrix other, DoubleMatrix result)` Elementwise division, with operands switched.
`DoubleMatrix`	`repmat(int rowMult, int columnMult)` Generate a new matrix which has the given number of replications of this.
`DoubleMatrix`	`reshape(int newRows, int newColumns)` Reshape the matrix.
`void`	`resize(int newRows, int newColumns)` Resize the matrix.
`int[]`	`rowArgmaxs()` Return index of minimal element per row.
`int[]`	`rowArgmins()` Return index of minimal element per row.
`DoubleMatrix`	`rowMaxs()` Return row-wise maximums.
`DoubleMatrix`	`rowMeans()` Return a vector containing the means of the rows.
`DoubleMatrix`	`rowMins()` Return row-wise minimums.
`List<DoubleMatrix>`	`rowsAsList()`
`int[][]`	`rowSortingPermutations()` Return matrix of indices which sort all columns.
`DoubleMatrix`	`rowSums()` Return a vector containing the sum of the rows.
`DoubleMatrix`	`rsub(double v)` (right-)subtract a scalar.
`DoubleMatrix`	`rsub(DoubleMatrix other)` (right-)subtract a matrix.
`DoubleMatrix`	`rsubi(double v)` (right-)subtract a scalar (in place).
`DoubleMatrix`	`rsubi(double a, DoubleMatrix result)` Subtract a matrix from a scalar (in-place).
`DoubleMatrix`	`rsubi(DoubleMatrix other)` (right-)subtract a matrix (in place).
`DoubleMatrix`	`rsubi(DoubleMatrix other, DoubleMatrix result)` Subtract two matrices, but subtract first from second matrix, that is, compute result = other - this (in-place).
`boolean`	`sameLength(DoubleMatrix a)` Checks whether two matrices have the same length.
`boolean`	`sameSize(DoubleMatrix a)` Checks whether two matrices have the same size.
`void`	`save(String filename)` Saves this matrix to the specified file.
`double`	`scalar()` Return the first element of the matrix.
`static DoubleMatrix`	`scalar(double s)` Create a 1-by-1 matrix.
`DoubleMatrix`	`select(DoubleMatrix where)`
`DoubleMatrix`	`selecti(DoubleMatrix where)`
`DoubleMatrix`	`sort()` Return a new matrix with all elements sorted.
`DoubleMatrix`	`sortColumns()` Sort columns.
`DoubleMatrix`	`sortColumnsi()` Sort columns (in-place).
`DoubleMatrix`	`sorti()` Sort elements in-place.
`int[]`	`sortingPermutation()` Get the sorting permutation.
`DoubleMatrix`	`sortRows()` Sort rows.
`DoubleMatrix`	`sortRowsi()` Sort rows (in-place).
`double`	`squaredDistance(DoubleMatrix other)` Returns the squared (Euclidean) distance.
`DoubleMatrix`	`sub(double v)` Subtract a scalar.
`DoubleMatrix`	`sub(DoubleMatrix other)` Subtract a matrix.
`DoubleMatrix`	`subColumnVector(DoubleMatrix x)` Subtract a vector from all columns of the matrix.
`DoubleMatrix`	`subi(double v)` Subtract a scalar (in place).
`DoubleMatrix`	`subi(double v, DoubleMatrix result)` Subtract a scalar from a matrix (in-place).
`DoubleMatrix`	`subi(DoubleMatrix other)` Subtract a matrix (in place).
`DoubleMatrix`	`subi(DoubleMatrix other, DoubleMatrix result)` Subtract two matrices (in-place).
`DoubleMatrix`	`subiColumnVector(DoubleMatrix x)` Subtract a column vector from all columns of the matrix (in-place).
`DoubleMatrix`	`subiRowVector(DoubleMatrix x)` Subtract a row vector from all rows of the matrix (in-place).
`DoubleMatrix`	`subRowVector(DoubleMatrix x)` Subtract a row vector from all rows of the matrix.
`double`	`sum()` Computes the sum of all elements of the matrix.
`DoubleMatrix`	`swapColumns(int i, int j)` Swap two columns of a matrix.
`DoubleMatrix`	`swapRows(int i, int j)` Swap two rows of a matrix.
`double[]`	`toArray()` Converts the matrix to a one-dimensional array of doubles.
`double[][]`	`toArray2()` Converts the matrix to a two-dimensional array of doubles.
`boolean[]`	`toBooleanArray()` Convert the matrix to a one-dimensional array of boolean values.
`boolean[][]`	`toBooleanArray2()` Convert the matrix to a two-dimensional array of boolean values.
`ComplexDoubleMatrix`	`toComplex()`
`FloatMatrix`	`toFloat()`
`int[]`	`toIntArray()` Converts the matrix to a one-dimensional array of integers.
`int[][]`	`toIntArray2()` Convert the matrix to a two-dimensional array of integers.
`String`	`toString()` Generate string representation of the matrix.
`String`	`toString(String fmt)` Generate string representation of the matrix, with specified format for the entries.
`String`	`toString(String fmt, String open, String close, String colSep, String rowSep)` Generate string representation of the matrix, with specified format for the entries, and delimiters.
`DoubleMatrix`	`transpose()` Return transposed copy of this matrix.
`DoubleMatrix`	`truth()` Maps zero to 0.0 and all non-zero values to 1.0.
`DoubleMatrix`	`truthi()` Maps zero to 0.0 and all non-zero values to 1.0 (in-place).
`static DoubleMatrix`	`valueOf(String text)` Construct DoubleMatrix from ASCII representation.
`DoubleMatrix`	`xor(double value)` Compute elementwise logical xor against a scalar.
`DoubleMatrix`	`xor(DoubleMatrix other)` Compute elementwise logical xor.
`DoubleMatrix`	`xori(double value)` Compute elementwise logical xor against a scalar (in-place).
`DoubleMatrix`	`xori(double value, DoubleMatrix result)` Compute elementwise logical xor against a scalar (in-place).
`DoubleMatrix`	`xori(DoubleMatrix other)` Compute elementwise logical xor (in-place).
`DoubleMatrix`	`xori(DoubleMatrix other, DoubleMatrix result)` Compute elementwise logical xor (in-place).
`static DoubleMatrix`	`zeros(int length)` Creates a column vector of given length.
`static DoubleMatrix`	`zeros(int rows, int columns)` Creates a new matrix in which all values are equal 0.

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail
- rows
```
public int rows
```
  Number of rows.
- columns
```
public int columns
```
  Number of columns.
- length
```
public int length
```
  Total number of elements (for convenience).
- data
```
public double[] data
```
  The actual data stored by rows (that is, row 0, row 1...).
- EMPTY
```
public static final DoubleMatrix EMPTY
```

Constructor Detail
- DoubleMatrix
```
public DoubleMatrix(int newRows,
                    int newColumns,
                    double... newData)
```
  Create a new matrix with newRows rows, newColumns columns using newData> as the data. Note that any change to the DoubleMatrix will change the input array, too.
  
  Parameters:
  
  newRows - the number of rows of the new matrix
  
  newColumns - the number of columns of the new matrix
  
  newData - the data array to be used. Data must be stored by column (column-major)
- DoubleMatrix
```
public DoubleMatrix(int newRows,
                    int newColumns)
```
  Creates a new n times m DoubleMatrix.
  
  Parameters:
  
  newRows - the number of rows (n) of the new matrix.
  
  newColumns - the number of columns (m) of the new matrix.
- DoubleMatrix
```
public DoubleMatrix()
```
  Creates a new DoubleMatrix of size 0 times 0.
- DoubleMatrix
```
public DoubleMatrix(int len)
```
  Create a Matrix of length len. This creates a column vector.
  
  Parameters:
  
  len -
- DoubleMatrix
```
public DoubleMatrix(double[] newData)
```
  Create a a column vector using newData as the data array. Note that any change to the created DoubleMatrix will change in input array.
- DoubleMatrix
```
public DoubleMatrix(String filename)
             throws IOException
```
  Creates a new matrix by reading it from a file.
  
  Parameters:
  
  filename - the path and name of the file to read the matrix from
  
  Throws:
  
  IOException
- DoubleMatrix
```
public DoubleMatrix(double[][] data)
```
  Creates a new n times m DoubleMatrix from the given n times m 2D data array. Note that the input array is copied and any change to the DoubleMatrix will not change the input array. The first dimension of the array makes the rows (n) and the second dimension the columns (m). For example, the given code
  
  new DoubleMatrix(new double[][]{{1d, 2d, 3d}, {4d, 5d, 6d}, {7d, 8d, 9d}}).print();
  
  will constructs the following matrix:
```
 1.0    2.0     3.0
 4.0    5.0     6.0
 7.0    8.0     9.0
 
```
  .
  Parameters:
  
  data - n times m data array
- DoubleMatrix
```
public DoubleMatrix(List<Double> data)
```
  Creates a DoubleMatrix column vector from the given List<Double&rt;.
  
  Parameters:
  
  data - data from which the entries are taken.

Method Detail

valueOf
```
public static DoubleMatrix valueOf(String text)
```
Construct DoubleMatrix from ASCII representation. This is not very fast, but can be quiet useful when you want to "just" construct a matrix, for example when testing. The format is semicolon separated rows of space separated values, for example "1 2 3; 4 5 6; 7 8 9".

rand

public static DoubleMatrix rand(int rows,
                                int columns)

Create matrix with random values uniformly in 0..1.

rand
```
public static DoubleMatrix rand(int len)
```
Creates a column vector with random values uniformly in 0..1.

randn

public static DoubleMatrix randn(int rows,
                                 int columns)

Create matrix with normally distributed random values.

randn
```
public static DoubleMatrix randn(int len)
```
Create column vector with normally distributed random values.

zeros

public static DoubleMatrix zeros(int rows,
                                 int columns)

Creates a new matrix in which all values are equal 0.

zeros

public static DoubleMatrix zeros(int length)

Creates a column vector of given length.

ones

public static DoubleMatrix ones(int rows,
                                int columns)

Creates a new matrix in which all values are equal 1.

ones
```
public static DoubleMatrix ones(int length)
```
Creates a column vector with all elements equal to 1.

eye

public static DoubleMatrix eye(int n)

Construct a new n-by-n identity matrix.

diag
```
public static DoubleMatrix diag(DoubleMatrix x)
```
Creates a new matrix where the values of the given vector are the diagonal values of the matrix.

diag
```
public static DoubleMatrix diag(DoubleMatrix x,
                                int rows,
                                int columns)
```
Construct a matrix of arbitrary shape and set the diagonal according to a passed vector. length of needs to be smaller than rows or columns.

Parameters:

x - vector to fill the diagonal with

rows - number of rows of the resulting matrix

columns - number of columns of the resulting matrix

Returns:

a matrix with dimensions rows * columns whose diagonal elements are filled by x

scalar
```
public static DoubleMatrix scalar(double s)
```
Create a 1-by-1 matrix. For many operations, this matrix functions like a normal double.

isScalar
```
public boolean isScalar()
```
Test whether a matrix is scalar.

scalar
```
public double scalar()
```
Return the first element of the matrix.

logspace
```
public static DoubleMatrix logspace(double lower,
                                    double upper,
                                    int size)
```
Construct a column vector whose entries are logarithmically spaced points from 10^lower to 10^upper using the specified number of steps

Parameters:

lower - starting exponent

upper - ending exponent

size - number of steps

Returns:

a column vector with (10^lower, ... 10^upper) with size many entries.

linspace
```
public static DoubleMatrix linspace(int lower,
                                    int upper,
                                    int size)
```
Construct a column vector whose entries are linearly spaced points from lower to upper with size many steps.

Parameters:

lower - starting value

upper - end value

size - number of steps

Returns:

a column vector of size (lower, ..., upper) with size many entries.

concatHorizontally

public static DoubleMatrix concatHorizontally(DoubleMatrix A,
                                              DoubleMatrix B)

Concatenates two matrices horizontally. Matrices must have identical numbers of rows.

concatVertically

public static DoubleMatrix concatVertically(DoubleMatrix A,
                                            DoubleMatrix B)

Concatenates two matrices vertically. Matrices must have identical numbers of columns.

get
```
public DoubleMatrix get(int[] indices)
```
Get all elements specified by the linear indices.

get

public DoubleMatrix get(int r,
                        int[] indices)

Get all elements for a given row and the specified columns.

get

public DoubleMatrix get(int[] indices,
                        int c)

Get all elements for a given column and the specified rows.

get

public DoubleMatrix get(int[] rindices,
                        int[] cindices)

Get all elements from the specified rows and columns.

get

public DoubleMatrix get(Range rs,
                        Range cs)

Get elements from specified rows and columns.

get

public DoubleMatrix get(Range rs,
                        int c)

get

public DoubleMatrix get(int r,
                        Range cs)

get
```
public DoubleMatrix get(DoubleMatrix indices)
```
Get elements specified by the non-zero entries of the passed matrix.

get

public DoubleMatrix get(int r,
                        DoubleMatrix indices)

Get elements from a row and columns as specified by the non-zero entries of a matrix.

get
```
public DoubleMatrix get(DoubleMatrix indices,
                        int c)
```
Get elements from a column and rows as specified by the non-zero entries of a matrix.

get

public DoubleMatrix get(DoubleMatrix rindices,
                        DoubleMatrix cindices)

Get elements from columns and rows as specified by the non-zero entries of the passed matrices.

getRange

public DoubleMatrix getRange(int a,
                             int b)

Return all elements with linear index a, a + 1, ..., b - 1.

getColumnRange

public DoubleMatrix getColumnRange(int r,
                                   int a,
                                   int b)

Get elements from a row and columns a to b.

getRowRange

public DoubleMatrix getRowRange(int a,
                                int b,
                                int c)

Get elements from a column and rows a/tt> to b.

getRange public DoubleMatrix getRange(int ra, int rb, int ca, int cb) Get elements from rows ra to rb and columns ca to cb. getRows public DoubleMatrix getRows(int[] rindices) Get whole rows from the passed indices. getRows public DoubleMatrix getRows(DoubleMatrix rindices) Get whole rows as specified by the non-zero entries of a matrix. getRows public DoubleMatrix getRows(Range indices, DoubleMatrix result) getRows public DoubleMatrix getRows(Range indices) getColumns public DoubleMatrix getColumns(int[] cindices) Get whole columns from the passed indices. getColumns public DoubleMatrix getColumns(DoubleMatrix cindices) Get whole columns as specified by the non-zero entries of a matrix. getColumns public DoubleMatrix getColumns(Range indices, DoubleMatrix result) Get whole columns as specified by Range. getColumns public DoubleMatrix getColumns(Range indices) checkLength public void checkLength(int l) Assert that the matrix has a certain length. Throws: SizeException checkRows public void checkRows(int r) Asserts that the matrix has a certain number of rows. Throws: SizeException checkColumns public void checkColumns(int c) Asserts that the amtrix has a certain number of columns. Throws: SizeException put public DoubleMatrix put(int[] indices, DoubleMatrix x) Set elements in linear ordering in the specified indices. For example, a.put(new int[]{ 1, 2, 0 }, new DoubleMatrix(3, 1, 2.0, 4.0, 8.0) does a.put(1, 2.0), a.put(2, 4.0), a.put(0, 8.0). put public DoubleMatrix put(int r, int[] indices, DoubleMatrix x) Set multiple elements in a row. put public DoubleMatrix put(int[] indices, int c, DoubleMatrix x) Set multiple elements in a row. put public DoubleMatrix put(int[] rindices, int[] cindices, DoubleMatrix x) Put a sub-matrix as specified by the indices. put public DoubleMatrix put(Range rs, Range cs, DoubleMatrix x) Put a matrix into specified indices. put public DoubleMatrix put(int[] indices, double v) Put a single value into the specified indices (linear adressing). put public DoubleMatrix put(int r, int[] indices, double v) Put a single value into a row and the specified columns. put public DoubleMatrix put(int[] indices, int c, double v) Put a single value into the specified rows of a column. put public DoubleMatrix put(int[] rindices, int[] cindices, double v) Put a single value into the specified rows and columns. put public DoubleMatrix put(DoubleMatrix indices, DoubleMatrix v) Put a sub-matrix into the indices specified by the non-zero entries of indices (linear adressing). put public DoubleMatrix put(int r, DoubleMatrix indices, DoubleMatrix v) Put a sub-vector into the specified columns (non-zero entries of indices) of a row. put public DoubleMatrix put(DoubleMatrix indices, int c, DoubleMatrix v) Put a sub-vector into the specified rows (non-zero entries of indices) of a column. put public DoubleMatrix put(DoubleMatrix rindices, DoubleMatrix cindices, DoubleMatrix v) Put a sub-matrix into the specified rows and columns (non-zero entries of rindices and cindices. put public DoubleMatrix put(DoubleMatrix indices, double v) Put a single value into the elements specified by the non-zero entries of indices (linear adressing). put public DoubleMatrix put(int r, DoubleMatrix indices, double v) Put a single value into the specified columns (non-zero entries of indices) of a row. put public DoubleMatrix put(DoubleMatrix indices, int c, double v) Put a single value into the specified rows (non-zero entries of indices) of a column. put public DoubleMatrix put(DoubleMatrix rindices, DoubleMatrix cindices, double v) Put a single value in the specified rows and columns (non-zero entries of rindices and cindices. findIndices public int[] findIndices() Find the linear indices of all non-zero elements. transpose public DoubleMatrix transpose() Return transposed copy of this matrix. compare public boolean compare(Object o, double tolerance) Compare two matrices. Returns true if and only if other is also a DoubleMatrix which has the same size and the maximal absolute difference in matrix elements is smaller than the specified tolerance equals public boolean equals(Object o) Overrides: equals in class Object hashCode public int hashCode() Overrides: hashCode in class Object resize public void resize(int newRows, int newColumns) Resize the matrix. All elements will be set to zero. reshape public DoubleMatrix reshape(int newRows, int newColumns) Reshape the matrix. Number of elements must not change. repmat public DoubleMatrix repmat(int rowMult, int columnMult) Generate a new matrix which has the given number of replications of this. sameSize public boolean sameSize(DoubleMatrix a) Checks whether two matrices have the same size. assertSameSize public void assertSameSize(DoubleMatrix a) Throws SizeException unless two matrices have the same size. multipliesWith public boolean multipliesWith(DoubleMatrix a) Checks whether two matrices can be multiplied (that is, number of columns of this must equal number of rows of a. assertMultipliesWith public void assertMultipliesWith(DoubleMatrix a) Throws SizeException unless matrices can be multiplied with one another. sameLength public boolean sameLength(DoubleMatrix a) Checks whether two matrices have the same length. assertSameLength public void assertSameLength(DoubleMatrix a) Throws SizeException unless matrices have the same length. copy public DoubleMatrix copy(DoubleMatrix a) Copy DoubleMatrix a to this. this a is resized if necessary. dup public DoubleMatrix dup() Returns a duplicate of this matrix. Geometry is the same (including offsets, transpose, etc.), but the buffer is not shared. swapColumns public DoubleMatrix swapColumns(int i, int j) Swap two columns of a matrix. swapRows public DoubleMatrix swapRows(int i, int j) Swap two rows of a matrix. put public DoubleMatrix put(int rowIndex, int columnIndex, double value) Set matrix element get public double get(int rowIndex, int columnIndex) Retrieve matrix element index public int index(int rowIndex, int columnIndex) Get index of an element indexRows public int indexRows(int i) Compute the row index of a linear index. indexColumns public int indexColumns(int i) Compute the column index of a linear index. get public double get(int i) Get a matrix element (linear indexing). put public DoubleMatrix put(int i, double v) Set a matrix element (linear indexing). fill public DoubleMatrix fill(double value) Set all elements to a value. getRows public int getRows() Get number of rows. getColumns public int getColumns() Get number of columns. getLength public int getLength() Get total number of elements. isEmpty public boolean isEmpty() Checks whether the matrix is empty. isSquare public boolean isSquare() Checks whether the matrix is square. assertSquare public void assertSquare() Throw SizeException unless matrix is square. isVector public boolean isVector() Checks whether the matrix is a vector. isRowVector public boolean isRowVector() Checks whether the matrix is a row vector. isColumnVector public boolean isColumnVector() Checks whether the matrix is a column vector. diag public DoubleMatrix diag() Returns the diagonal of the matrix. print public void print() Pretty-print this matrix to System.out. toString public String toString() Generate string representation of the matrix. Overrides: toString in class Object toString public String toString(String fmt) Generate string representation of the matrix, with specified format for the entries. For example, x.toString("%.1f") generates a string representations having only one position after the decimal point. toString public String toString(String fmt, String open, String close, String colSep, String rowSep) Generate string representation of the matrix, with specified format for the entries, and delimiters. Parameters: fmt - entry format (passed to String.format()) open - opening parenthesis close - closing parenthesis colSep - separator between columns rowSep - separator between rows toArray public double[] toArray() Converts the matrix to a one-dimensional array of doubles. toArray2 public double[][] toArray2() Converts the matrix to a two-dimensional array of doubles. toIntArray public int[] toIntArray() Converts the matrix to a one-dimensional array of integers. toIntArray2 public int[][] toIntArray2() Convert the matrix to a two-dimensional array of integers. toBooleanArray public boolean[] toBooleanArray() Convert the matrix to a one-dimensional array of boolean values. toBooleanArray2 public boolean[][] toBooleanArray2() Convert the matrix to a two-dimensional array of boolean values. toFloat public FloatMatrix toFloat() elementsAsList public List<Double> elementsAsList() rowsAsList public List<DoubleMatrix> rowsAsList() columnsAsList public List<DoubleMatrix> columnsAsList() addi public DoubleMatrix addi(DoubleMatrix other, DoubleMatrix result) Add two matrices (in-place). addi public DoubleMatrix addi(double v, DoubleMatrix result) Add a scalar to a matrix (in-place). subi public DoubleMatrix subi(DoubleMatrix other, DoubleMatrix result) Subtract two matrices (in-place). subi public DoubleMatrix subi(double v, DoubleMatrix result) Subtract a scalar from a matrix (in-place). rsubi public DoubleMatrix rsubi(DoubleMatrix other, DoubleMatrix result) Subtract two matrices, but subtract first from second matrix, that is, compute result = other - this (in-place). rsubi public DoubleMatrix rsubi(double a, DoubleMatrix result) Subtract a matrix from a scalar (in-place). muli public DoubleMatrix muli(DoubleMatrix other, DoubleMatrix result) Elementwise multiplication (in-place). muli public DoubleMatrix muli(double v, DoubleMatrix result) Elementwise multiplication with a scalar (in-place). mmuli public DoubleMatrix mmuli(DoubleMatrix other, DoubleMatrix result) Matrix-matrix multiplication (in-place). mmuli public DoubleMatrix mmuli(double v, DoubleMatrix result) Matrix-matrix multiplication with a scalar (for symmetry, does the same as muli(scalar) (in-place). divi public DoubleMatrix divi(DoubleMatrix other, DoubleMatrix result) Elementwise division (in-place). divi public DoubleMatrix divi(double a, DoubleMatrix result) Elementwise division with a scalar (in-place). rdivi public DoubleMatrix rdivi(DoubleMatrix other, DoubleMatrix result) Elementwise division, with operands switched. Computes result = other / this (in-place). rdivi public DoubleMatrix rdivi(double a, DoubleMatrix result) (Elementwise) division with a scalar, with operands switched. Computes result = a / this (in-place). negi public DoubleMatrix negi() Negate each element (in-place). neg public DoubleMatrix neg() Negate each element. noti public DoubleMatrix noti() Maps zero to 1.0 and all non-zero values to 0.0 (in-place). not public DoubleMatrix not() Maps zero to 1.0 and all non-zero values to 0.0. truthi public DoubleMatrix truthi() Maps zero to 0.0 and all non-zero values to 1.0 (in-place). truth public DoubleMatrix truth() Maps zero to 0.0 and all non-zero values to 1.0. isNaNi public DoubleMatrix isNaNi() isNaN public DoubleMatrix isNaN() isInfinitei public DoubleMatrix isInfinitei() isInfinite public DoubleMatrix isInfinite() isLowerTriangular public boolean isLowerTriangular() Checks whether all entries (i, j) with i >= j are zero. isUpperTriangular public boolean isUpperTriangular() Checks whether all entries (i, j) with i <= j are zero. selecti public DoubleMatrix selecti(DoubleMatrix where) select public DoubleMatrix select(DoubleMatrix where) rankOneUpdate public DoubleMatrix rankOneUpdate(double alpha, DoubleMatrix x, DoubleMatrix y) Computes a rank-1-update A = A + alpha * x * y'. rankOneUpdate public DoubleMatrix rankOneUpdate(double alpha, DoubleMatrix x) Computes a rank-1-update A = A + alpha * x * x'. rankOneUpdate public DoubleMatrix rankOneUpdate(DoubleMatrix x) Computes a rank-1-update A = A + x * x'. rankOneUpdate public DoubleMatrix rankOneUpdate(DoubleMatrix x, DoubleMatrix y) Computes a rank-1-update A = A + x * y'. min public double min() Returns the minimal element of the matrix. argmin public int argmin() Returns the linear index of the minimal element. If there are more than one elements with this value, the first one is returned. mini public DoubleMatrix mini(DoubleMatrix other, DoubleMatrix result) Computes the minimum between two matrices. Returns the smaller of the corresponding elements in the matrix (in-place). mini public DoubleMatrix mini(DoubleMatrix other) Computes the minimum between two matrices. Returns the smaller of the corresponding elements in the matrix (in-place on this). min public DoubleMatrix min(DoubleMatrix other) Computes the minimum between two matrices. Returns the smaller of the corresponding elements in the matrix (in-place on this). mini public DoubleMatrix mini(double v, DoubleMatrix result) mini public DoubleMatrix mini(double v) min public DoubleMatrix min(double v) max public double max() Returns the maximal element of the matrix. argmax public int argmax() Returns the linear index of the maximal element of the matrix. If there are more than one elements with this value, the first one is returned. maxi public DoubleMatrix maxi(DoubleMatrix other, DoubleMatrix result) Computes the maximum between two matrices. Returns the larger of the corresponding elements in the matrix (in-place). maxi public DoubleMatrix maxi(DoubleMatrix other) Computes the maximum between two matrices. Returns the smaller of the corresponding elements in the matrix (in-place on this). max public DoubleMatrix max(DoubleMatrix other) Computes the maximum between two matrices. Returns the larger of the corresponding elements in the matrix (in-place on this). maxi public DoubleMatrix maxi(double v, DoubleMatrix result) maxi public DoubleMatrix maxi(double v) max public DoubleMatrix max(double v) sum public double sum() Computes the sum of all elements of the matrix. prod public double prod() Computes the product of all elements of the matrix mean public double mean() Computes the mean value of all elements in the matrix, that is, x.sum() / x.length. cumulativeSumi public DoubleMatrix cumulativeSumi() Computes the cumulative sum, that is, the sum of all elements of the matrix up to a given index in linear addressing (in-place). cumulativeSum public DoubleMatrix cumulativeSum() Computes the cumulative sum, that is, the sum of all elements of the matrix up to a given index in linear addressing. dot public double dot(DoubleMatrix other) The scalar product of this with other. project public double project(DoubleMatrix other) Computes the projection coefficient of other on this. The returned scalar times this is the orthogonal projection of other on this. norm2 public double norm2() The Euclidean norm of the matrix as vector, also the Frobenius norm of the matrix. normmax public double normmax() The maximum norm of the matrix (maximal absolute value of the elements). norm1 public double norm1() The 1-norm of the matrix as vector (sum of absolute values of elements). squaredDistance public double squaredDistance(DoubleMatrix other) Returns the squared (Euclidean) distance. distance2 public double distance2(DoubleMatrix other) Returns the (euclidean) distance. distance1 public double distance1(DoubleMatrix other) Returns the (1-norm) distance. sort public DoubleMatrix sort() Return a new matrix with all elements sorted. sorti public DoubleMatrix sorti() Sort elements in-place. sortingPermutation public int[] sortingPermutation() Get the sorting permutation. Returns: an int[] array such that which indexes the elements in sorted order. sortColumnsi public DoubleMatrix sortColumnsi() Sort columns (in-place). sortColumns public DoubleMatrix sortColumns() Sort columns. columnSortingPermutations public int[][] columnSortingPermutations() Return matrix of indices which sort all columns. sortRowsi public DoubleMatrix sortRowsi() Sort rows (in-place). sortRows public DoubleMatrix sortRows() Sort rows. rowSortingPermutations public int[][] rowSortingPermutations() Return matrix of indices which sort all columns. columnSums public DoubleMatrix columnSums() Return a vector containing the sums of the columns (having number of columns many entries) columnMeans public DoubleMatrix columnMeans() Return a vector containing the means of all columns. rowSums public DoubleMatrix rowSums() Return a vector containing the sum of the rows. rowMeans public DoubleMatrix rowMeans() Return a vector containing the means of the rows. getColumn public DoubleMatrix getColumn(int c) Get a copy of a column. getColumn public DoubleMatrix getColumn(int c, DoubleMatrix result) Copy a column to the given vector. putColumn public void putColumn(int c, DoubleMatrix v) Copy a column back into the matrix. getRow public DoubleMatrix getRow(int r) Get a copy of a row. getRow public DoubleMatrix getRow(int r, DoubleMatrix result) Copy a row to a given vector. putRow public void putRow(int r, DoubleMatrix v) Copy a row back into the matrix. columnMins public DoubleMatrix columnMins() Return column-wise minimums. columnArgmins public int[] columnArgmins() Return index of minimal element per column. columnMaxs public DoubleMatrix columnMaxs() Return column-wise maximums. columnArgmaxs public int[] columnArgmaxs() Return index of minimal element per column. rowMins public DoubleMatrix rowMins() Return row-wise minimums. rowArgmins public int[] rowArgmins() Return index of minimal element per row. rowMaxs public DoubleMatrix rowMaxs() Return row-wise maximums. rowArgmaxs public int[] rowArgmaxs() Return index of minimal element per row. addiRowVector public DoubleMatrix addiRowVector(DoubleMatrix x) Add a row vector to all rows of the matrix (in place). addRowVector public DoubleMatrix addRowVector(DoubleMatrix x) Add a row to all rows of the matrix. addiColumnVector public DoubleMatrix addiColumnVector(DoubleMatrix x) Add a vector to all columns of the matrix (in-place). addColumnVector public DoubleMatrix addColumnVector(DoubleMatrix x) Add a vector to all columns of the matrix. subiRowVector public DoubleMatrix subiRowVector(DoubleMatrix x) Subtract a row vector from all rows of the matrix (in-place). subRowVector public DoubleMatrix subRowVector(DoubleMatrix x) Subtract a row vector from all rows of the matrix. subiColumnVector public DoubleMatrix subiColumnVector(DoubleMatrix x) Subtract a column vector from all columns of the matrix (in-place). subColumnVector public DoubleMatrix subColumnVector(DoubleMatrix x) Subtract a vector from all columns of the matrix. mulRow public DoubleMatrix mulRow(int r, double scale) Multiply a row by a scalar. mulColumn public DoubleMatrix mulColumn(int c, double scale) Multiply a column by a scalar. muliColumnVector public DoubleMatrix muliColumnVector(DoubleMatrix x) Multiply all columns with a column vector (in-place). mulColumnVector public DoubleMatrix mulColumnVector(DoubleMatrix x) Multiply all columns with a column vector. muliRowVector public DoubleMatrix muliRowVector(DoubleMatrix x) Multiply all rows with a row vector (in-place). mulRowVector public DoubleMatrix mulRowVector(DoubleMatrix x) Multiply all rows with a row vector. diviRowVector public DoubleMatrix diviRowVector(DoubleMatrix x) divRowVector public DoubleMatrix divRowVector(DoubleMatrix x) diviColumnVector public DoubleMatrix diviColumnVector(DoubleMatrix x) divColumnVector public DoubleMatrix divColumnVector(DoubleMatrix x) out public void out(DataOutputStream dos) throws IOException Writes out this matrix to the given data stream. Parameters: dos - the data output stream to write to. Throws: IOException in public void in(DataInputStream dis) throws IOException Reads in a matrix from the given data stream. Note that the old data of this matrix will be discarded. Parameters: dis - the data input stream to read from. Throws: IOException save public void save(String filename) throws IOException Saves this matrix to the specified file. Parameters: filename - the file to write the matrix in. Throws: IOException - thrown on errors while writing the matrix to the file load public void load(String filename) throws IOException Loads a matrix from a file into this matrix. Note that the old data of this matrix will be discarded. Parameters: filename - the file to read the matrix from Throws: IOException - thrown on errors while reading the matrix loadAsciiFile public static DoubleMatrix loadAsciiFile(String filename) throws IOException Throws: IOException loadCSVFile public static DoubleMatrix loadCSVFile(String filename) throws IOException Throws: IOException addi public DoubleMatrix addi(DoubleMatrix other) Add a matrix (in place). add public DoubleMatrix add(DoubleMatrix other) Add a matrix. addi public DoubleMatrix addi(double v) Add a scalar (in place). add public DoubleMatrix add(double v) Add a scalar. subi public DoubleMatrix subi(DoubleMatrix other) Subtract a matrix (in place). sub public DoubleMatrix sub(DoubleMatrix other) Subtract a matrix. subi public DoubleMatrix subi(double v) Subtract a scalar (in place). sub public DoubleMatrix sub(double v) Subtract a scalar. rsubi public DoubleMatrix rsubi(DoubleMatrix other) (right-)subtract a matrix (in place). rsub public DoubleMatrix rsub(DoubleMatrix other) (right-)subtract a matrix. rsubi public DoubleMatrix rsubi(double v) (right-)subtract a scalar (in place). rsub public DoubleMatrix rsub(double v) (right-)subtract a scalar. divi public DoubleMatrix divi(DoubleMatrix other) Elementwise divide by a matrix (in place). div public DoubleMatrix div(DoubleMatrix other) Elementwise divide by a matrix. divi public DoubleMatrix divi(double v) Elementwise divide by a scalar (in place). div public DoubleMatrix div(double v) Elementwise divide by a scalar. rdivi public DoubleMatrix rdivi(DoubleMatrix other) (right-)elementwise divide by a matrix (in place). rdiv public DoubleMatrix rdiv(DoubleMatrix other) (right-)elementwise divide by a matrix. rdivi public DoubleMatrix rdivi(double v) (right-)elementwise divide by a scalar (in place). rdiv public DoubleMatrix rdiv(double v) (right-)elementwise divide by a scalar. muli public DoubleMatrix muli(DoubleMatrix other) Elementwise multiply by a matrix (in place). mul public DoubleMatrix mul(DoubleMatrix other) Elementwise multiply by a matrix. muli public DoubleMatrix muli(double v) Elementwise multiply by a scalar (in place). mul public DoubleMatrix mul(double v) Elementwise multiply by a scalar. mmuli public DoubleMatrix mmuli(DoubleMatrix other) Matrix-multiply by a matrix (in place). mmul public DoubleMatrix mmul(DoubleMatrix other) Matrix-multiply by a matrix. mmuli public DoubleMatrix mmuli(double v) Matrix-multiply by a scalar (in place). mmul public DoubleMatrix mmul(double v) Matrix-multiply by a scalar. lti public DoubleMatrix lti(DoubleMatrix other, DoubleMatrix result) Test for "less than" (in-place). lti public DoubleMatrix lti(DoubleMatrix other) Test for "less than" (in-place). lt public DoubleMatrix lt(DoubleMatrix other) Test for "less than". lti public DoubleMatrix lti(double value, DoubleMatrix result) Test for "less than" against a scalar (in-place). lti public DoubleMatrix lti(double value) Test for "less than" against a scalar (in-place). lt public DoubleMatrix lt(double value) test for "less than" against a scalar. gti public DoubleMatrix gti(DoubleMatrix other, DoubleMatrix result) Test for "greater than" (in-place). gti public DoubleMatrix gti(DoubleMatrix other) Test for "greater than" (in-place). gt public DoubleMatrix gt(DoubleMatrix other) Test for "greater than". gti public DoubleMatrix gti(double value, DoubleMatrix result) Test for "greater than" against a scalar (in-place). gti public DoubleMatrix gti(double value) Test for "greater than" against a scalar (in-place). gt public DoubleMatrix gt(double value) test for "greater than" against a scalar. lei public DoubleMatrix lei(DoubleMatrix other, DoubleMatrix result) Test for "less than or equal" (in-place). lei public DoubleMatrix lei(DoubleMatrix other) Test for "less than or equal" (in-place). le public DoubleMatrix le(DoubleMatrix other) Test for "less than or equal". lei public DoubleMatrix lei(double value, DoubleMatrix result) Test for "less than or equal" against a scalar (in-place). lei public DoubleMatrix lei(double value) Test for "less than or equal" against a scalar (in-place). le public DoubleMatrix le(double value) test for "less than or equal" against a scalar. gei public DoubleMatrix gei(DoubleMatrix other, DoubleMatrix result) Test for "greater than or equal" (in-place). gei public DoubleMatrix gei(DoubleMatrix other) Test for "greater than or equal" (in-place). ge public DoubleMatrix ge(DoubleMatrix other) Test for "greater than or equal". gei public DoubleMatrix gei(double value, DoubleMatrix result) Test for "greater than or equal" against a scalar (in-place). gei public DoubleMatrix gei(double value) Test for "greater than or equal" against a scalar (in-place). ge public DoubleMatrix ge(double value) test for "greater than or equal" against a scalar. eqi public DoubleMatrix eqi(DoubleMatrix other, DoubleMatrix result) Test for equality (in-place). eqi public DoubleMatrix eqi(DoubleMatrix other) Test for equality (in-place). eq public DoubleMatrix eq(DoubleMatrix other) Test for equality. eqi public DoubleMatrix eqi(double value, DoubleMatrix result) Test for equality against a scalar (in-place). eqi public DoubleMatrix eqi(double value) Test for equality against a scalar (in-place). eq public DoubleMatrix eq(double value) test for equality against a scalar. nei public DoubleMatrix nei(DoubleMatrix other, DoubleMatrix result) Test for inequality (in-place). nei public DoubleMatrix nei(DoubleMatrix other) Test for inequality (in-place). ne public DoubleMatrix ne(DoubleMatrix other) Test for inequality. nei public DoubleMatrix nei(double value, DoubleMatrix result) Test for inequality against a scalar (in-place). nei public DoubleMatrix nei(double value) Test for inequality against a scalar (in-place). ne public DoubleMatrix ne(double value) test for inequality against a scalar. andi public DoubleMatrix andi(DoubleMatrix other, DoubleMatrix result) Compute elementwise logical and (in-place). andi public DoubleMatrix andi(DoubleMatrix other) Compute elementwise logical and (in-place). and public DoubleMatrix and(DoubleMatrix other) Compute elementwise logical and. andi public DoubleMatrix andi(double value, DoubleMatrix result) Compute elementwise logical and against a scalar (in-place). andi public DoubleMatrix andi(double value) Compute elementwise logical and against a scalar (in-place). and public DoubleMatrix and(double value) Compute elementwise logical and against a scalar. ori public DoubleMatrix ori(DoubleMatrix other, DoubleMatrix result) Compute elementwise logical or (in-place). ori public DoubleMatrix ori(DoubleMatrix other) Compute elementwise logical or (in-place). or public DoubleMatrix or(DoubleMatrix other) Compute elementwise logical or. ori public DoubleMatrix ori(double value, DoubleMatrix result) Compute elementwise logical or against a scalar (in-place). ori public DoubleMatrix ori(double value) Compute elementwise logical or against a scalar (in-place). or public DoubleMatrix or(double value) Compute elementwise logical or against a scalar. xori public DoubleMatrix xori(DoubleMatrix other, DoubleMatrix result) Compute elementwise logical xor (in-place). xori public DoubleMatrix xori(DoubleMatrix other) Compute elementwise logical xor (in-place). xor public DoubleMatrix xor(DoubleMatrix other) Compute elementwise logical xor. xori public DoubleMatrix xori(double value, DoubleMatrix result) Compute elementwise logical xor against a scalar (in-place). xori public DoubleMatrix xori(double value) Compute elementwise logical xor against a scalar (in-place). xor public DoubleMatrix xor(double value) Compute elementwise logical xor against a scalar. toComplex public ComplexDoubleMatrix toComplex()

Class DoubleMatrix

Construction

Element Access, Copying and Duplication

Size and Shape

Arithmetics

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

rows

columns

length

data

EMPTY

Constructor Detail

DoubleMatrix

DoubleMatrix

DoubleMatrix

DoubleMatrix

DoubleMatrix

DoubleMatrix

DoubleMatrix

DoubleMatrix

Method Detail

valueOf

rand

rand

randn

randn

zeros

zeros

ones

ones

eye

diag

diag

scalar

isScalar

scalar

logspace

linspace

concatHorizontally

concatVertically

get

get

get

get

get

get

get

get

get

get

get

getRange

getColumnRange

getRowRange

getRange

getRows

getRows

getRows

getRows

getColumns

getColumns

getColumns

getColumns

checkLength

checkRows

checkColumns

put

put

put

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put

put

put

put

put