Package org.jblas

Class DoubleMatrix

  • All Implemented Interfaces:
    java.io.Serializable
    public class DoubleMatrix
extends java.lang.Object
implements java.io.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.

    MethodDescription
    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.
    Matrix constructors.

    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.
    Column vector constructors.

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

    MethodDescription
    x.concatHorizontally(y)New matrix will be x next to y.
    x.concatVertically(y)New matrix will be x atop y.
    Matrix concatenation.

    Element Access, Copying and Duplication

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

    x.MethodDescription
    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.
    Element access.

    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.
    Range objects.

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

    MethodDescription
    x.dup()Get a copy of x.
    x.copy(y)Copy the contents of y to x (possible resizing x).
    Copying matrices.

    Size and Shape

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

    x.MethodDescription
    x.rowsNumber of rows.
    x.columnsNumber of columns.
    x.lengthTotal 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.
    Size and size checks.

    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()
    Basic arithmetics.

    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.addColumnVectoradds a vector to each column
    x.subRowVector subtracts a vector from each row
    x.subColumnVectorsubtracts a vector from each column
    x.mulRowVector Multiplies each row by a vector (elementwise)
    x.mulColumnVectorMultiplies each column by a vector (elementwise)
    x.divRowVector Divide each row by a vector (elementwise)
    x.divColumnVectorDivide each column by a vector (elementwise)
    x.mulRow Multiplies a row by a scalar
    x.mulColumn Multiplies a column by a scalar
    Row and column arithmetics.

    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)
    Comparison operations.

    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()
    Logical operations.

    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 smallest 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
    Minimum and maximum.
    See Also:
    Serialized Form

    • 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...).

      • SEMICOLON

        private static final java.util.regex.Pattern SEMICOLON

      • WHITESPACES

        private static final java.util.regex.Pattern WHITESPACES

      • COMMA

        private static final java.util.regex.Pattern COMMA

    • 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​(java.lang.String filename)
             throws java.io.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:
        java.io.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​(java.util.List<java.lang.Double> data)
        Creates a DoubleMatrix column vector from the given List<Double>.
        Parameters:
        data - data from which the entries are taken.

    • Method Detail

      • valueOf

        public static DoubleMatrix valueOf​(java.lang.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".

      • writeObject

        private void writeObject​(java.io.ObjectOutputStream s)
                  throws java.io.IOException
        Serialization
        Throws:
        java.io.IOException

      • readObject

        private void readObject​(java.io.ObjectInputStream s)
                 throws java.io.IOException,
                        java.lang.ClassNotFoundException
        Throws:
        java.io.IOException
        java.lang.ClassNotFoundException

      • 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​(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.

      • 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 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.

      • 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.

      • 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[] rindices,
                        int[] cindices,
                        DoubleMatrix x)
        Put a sub-matrix as specified by the 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,
                        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​(java.lang.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​(java.lang.Object o)
        Overrides:
        equals in class java.lang.Object

      • hashCode

        public int hashCode()
        Overrides:
        hashCode in class java.lang.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.

      • 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 java.lang.String toString()
        Generate string representation of the matrix.
        Overrides:
        toString in class java.lang.Object

      • toString

        public java.lang.String toString​(java.lang.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 java.lang.String toString​(java.lang.String fmt,
                                 java.lang.String open,
                                 java.lang.String close,
                                 java.lang.String colSep,
                                 java.lang.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.

      • elementsAsList

        public java.util.List<java.lang.Double> elementsAsList()

      • rowsAsList

        public java.util.List<DoubleMatrix> rowsAsList()

      • columnsAsList

        public java.util.List<DoubleMatrix> columnsAsList()

      • ensureResultLength

        private void ensureResultLength​(DoubleMatrix other,
                                DoubleMatrix result)
        Ensures that the result vector has the same length as this. If not, resizing result is tried, which fails if result == this or result == other.

      • 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).

      • muli

        public DoubleMatrix muli​(double v,
                         DoubleMatrix result)
        Elementwise multiplication with a scalar (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).

      • 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).

      • 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.

      • 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.

      • rankOneUpdate

        public DoubleMatrix rankOneUpdate​(double alpha,
                                  DoubleMatrix x)
        Computes a rank-1-update A = A + alpha * x * x'.

      • 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).

      • 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).

      • 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).

      • 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.

      • 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.

      • 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 maximum element per row.

      • addiRowVector

        public DoubleMatrix addiRowVector​(DoubleMatrix x)
        Add a row vector to all rows of the matrix (in place).

      • addiColumnVector

        public DoubleMatrix addiColumnVector​(DoubleMatrix x)
        Add a vector to all columns of the matrix (in-place).

      • 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).

      • out

        public void out​(java.io.DataOutputStream dos)
         throws java.io.IOException
        Writes out this matrix to the given data stream.
        Parameters:
        dos - the data output stream to write to.
        Throws:
        java.io.IOException

      • in

        public void in​(java.io.DataInputStream dis)
        throws java.io.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:
        java.io.IOException

      • save

        public void save​(java.lang.String filename)
          throws java.io.IOException
        Saves this matrix to the specified file.
        Parameters:
        filename - the file to write the matrix in.
        Throws:
        java.io.IOException - thrown on errors while writing the matrix to the file

      • load

        public void load​(java.lang.String filename)
          throws java.io.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:
        java.io.IOException - thrown on errors while reading the matrix

      • loadAsciiFile

        public static DoubleMatrix loadAsciiFile​(java.lang.String filename)
                                  throws java.io.IOException
        Throws:
        java.io.IOException

      • loadCSVFile

        public static DoubleMatrix loadCSVFile​(java.lang.String filename)
                                throws java.io.IOException
        Throws:
        java.io.IOException

      • addi

        public DoubleMatrix addi​(double v)
        Add a scalar (in place).

      • subi

        public DoubleMatrix subi​(double v)
        Subtract a scalar (in place).

      • sub

        public DoubleMatrix sub​(double v)
        Subtract a scalar.

      • 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​(double v)
        Elementwise divide by a scalar (in place).

      • div

        public DoubleMatrix div​(double v)
        Elementwise divide by a scalar.

      • 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​(double v)
        Elementwise multiply by a scalar (in place).

      • mul

        public DoubleMatrix mul​(double v)
        Elementwise multiply by a scalar.

      • 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​(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​(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​(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​(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​(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​(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​(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​(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​(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.