Class WrapperDoubleMatrix2D

    • Constructor Detail

      • WrapperDoubleMatrix2D

        public WrapperDoubleMatrix2D​(DoubleMatrix2D newContent)
        Constructs a matrix with a copy of the given values. values is required to have the form values[row][column] and have exactly the same number of columns in every row.

        The values are copied. So subsequent changes in values are not reflected in the matrix, and vice-versa.

        Parameters:
        values - The values to be filled into the new matrix.
        Throws:
        java.lang.IllegalArgumentException - if for any 1 <= row < values.length: values[row].length != values[row-1].length.
    • Method Detail

      • getContent

        protected DoubleMatrix2D getContent()
        Returns the content of this matrix if it is a wrapper; or this otherwise. Override this method in wrappers.
        Overrides:
        getContent in class DoubleMatrix2D
      • getQuick

        public double getQuick​(int row,
                               int column)
        Returns the matrix cell value at coordinate [row,column].

        Provided with invalid parameters this method may return invalid objects without throwing any exception. You should only use this method when you are absolutely sure that the coordinate is within bounds. Precondition (unchecked): 0 <= column < columns() && 0 <= row < rows().

        Specified by:
        getQuick in class DoubleMatrix2D
        Parameters:
        row - the index of the row-coordinate.
        column - the index of the column-coordinate.
        Returns:
        the value at the specified coordinate.
      • like

        public DoubleMatrix2D like​(int rows,
                                   int columns)
        Construct and returns a new empty matrix of the same dynamic type as the receiver, having the specified number of rows and columns. For example, if the receiver is an instance of type DenseDoubleMatrix2D the new matrix must also be of type DenseDoubleMatrix2D, if the receiver is an instance of type SparseDoubleMatrix2D the new matrix must also be of type SparseDoubleMatrix2D, etc. In general, the new matrix should have internal parametrization as similar as possible.
        Specified by:
        like in class DoubleMatrix2D
        Parameters:
        rows - the number of rows the matrix shall have.
        columns - the number of columns the matrix shall have.
        Returns:
        a new empty matrix of the same dynamic type.
      • like1D

        public DoubleMatrix1D like1D​(int size)
        Construct and returns a new 1-d matrix of the corresponding dynamic type, entirelly independent of the receiver. For example, if the receiver is an instance of type DenseDoubleMatrix2D the new matrix must be of type DenseDoubleMatrix1D, if the receiver is an instance of type SparseDoubleMatrix2D the new matrix must be of type SparseDoubleMatrix1D, etc.
        Specified by:
        like1D in class DoubleMatrix2D
        Parameters:
        size - the number of cells the matrix shall have.
        Returns:
        a new matrix of the corresponding dynamic type.
      • like1D

        protected DoubleMatrix1D like1D​(int size,
                                        int offset,
                                        int stride)
        Construct and returns a new 1-d matrix of the corresponding dynamic type, sharing the same cells. For example, if the receiver is an instance of type DenseDoubleMatrix2D the new matrix must be of type DenseDoubleMatrix1D, if the receiver is an instance of type SparseDoubleMatrix2D the new matrix must be of type SparseDoubleMatrix1D, etc.
        Specified by:
        like1D in class DoubleMatrix2D
        Parameters:
        size - the number of cells the matrix shall have.
        offset - the index of the first element.
        stride - the number of indexes between any two elements, i.e. index(i+1)-index(i).
        Returns:
        a new matrix of the corresponding dynamic type.
      • setQuick

        public void setQuick​(int row,
                             int column,
                             double value)
        Sets the matrix cell at coordinate [row,column] to the specified value.

        Provided with invalid parameters this method may access illegal indexes without throwing any exception. You should only use this method when you are absolutely sure that the coordinate is within bounds. Precondition (unchecked): 0 <= column < columns() && 0 <= row < rows().

        Specified by:
        setQuick in class DoubleMatrix2D
        Parameters:
        row - the index of the row-coordinate.
        column - the index of the column-coordinate.
        value - the value to be filled into the specified cell.
      • viewColumn

        public DoubleMatrix1D viewColumn​(int column)
        Constructs and returns a new slice view representing the rows of the given column. The returned view is backed by this matrix, so changes in the returned view are reflected in this matrix, and vice-versa. To obtain a slice view on subranges, construct a sub-ranging view (viewPart(...)), then apply this method to the sub-range view.

        Example:

        2 x 3 matrix:
        1, 2, 3
        4, 5, 6
        viewColumn(0) ==> Matrix1D of size 2:
        1, 4
        Overrides:
        viewColumn in class DoubleMatrix2D
        Parameters:
        column - the column to fix.
        Returns:
        a new slice view.
        Throws:
        java.lang.IndexOutOfBoundsException - if column < 0 || column >= columns().
        See Also:
        viewRow(int)
      • viewColumnFlip

        public DoubleMatrix2D viewColumnFlip()
        Constructs and returns a new flip view along the column axis. What used to be column 0 is now column columns()-1, ..., what used to be column columns()-1 is now column 0. The returned view is backed by this matrix, so changes in the returned view are reflected in this matrix, and vice-versa.

        Example:

        2 x 3 matrix:
        1, 2, 3
        4, 5, 6
        columnFlip ==> 2 x 3 matrix:
        3, 2, 1
        6, 5, 4
        columnFlip ==> 2 x 3 matrix:
        1, 2, 3
        4, 5, 6
        Overrides:
        viewColumnFlip in class DoubleMatrix2D
        Returns:
        a new flip view.
        See Also:
        viewRowFlip()
      • viewDice

        public DoubleMatrix2D viewDice()
        Constructs and returns a new dice (transposition) view; Swaps axes; example: 3 x 4 matrix --> 4 x 3 matrix. The view has both dimensions exchanged; what used to be columns become rows, what used to be rows become columns. In other words: view.get(row,column)==this.get(column,row). This is a zero-copy transposition, taking O(1), i.e. constant time. The returned view is backed by this matrix, so changes in the returned view are reflected in this matrix, and vice-versa. Use idioms like result = viewDice(A).copy() to generate an independent transposed matrix.

        Example:

        2 x 3 matrix:
        1, 2, 3
        4, 5, 6
        transpose ==> 3 x 2 matrix:
        1, 4
        2, 5
        3, 6
        transpose ==> 2 x 3 matrix:
        1, 2, 3
        4, 5, 6
        Overrides:
        viewDice in class DoubleMatrix2D
        Returns:
        a new dice view.
      • viewPart

        public DoubleMatrix2D viewPart​(int row,
                                       int column,
                                       int height,
                                       int width)
        Constructs and returns a new sub-range view that is a height x width sub matrix starting at [row,column]. Operations on the returned view can only be applied to the restricted range. Any attempt to access coordinates not contained in the view will throw an IndexOutOfBoundsException.

        Note that the view is really just a range restriction: The returned matrix is backed by this matrix, so changes in the returned matrix are reflected in this matrix, and vice-versa.

        The view contains the cells from [row,column] to [row+height-1,column+width-1], all inclusive. and has view.rows() == height; view.columns() == width;. A view's legal coordinates are again zero based, as usual. In other words, legal coordinates of the view range from [0,0] to [view.rows()-1==height-1,view.columns()-1==width-1]. As usual, any attempt to access a cell at a coordinate column<0 || column>=view.columns() || row<0 || row>=view.rows() will throw an IndexOutOfBoundsException.

        Overrides:
        viewPart in class DoubleMatrix2D
        Parameters:
        row - The index of the row-coordinate.
        column - The index of the column-coordinate.
        height - The height of the box.
        width - The width of the box.
        Returns:
        the new view.
        Throws:
        java.lang.IndexOutOfBoundsException - if column<0 || width<0 || column+width>columns() || row<0 || height<0 || row+height>rows()
      • viewRow

        public DoubleMatrix1D viewRow​(int row)
        Constructs and returns a new slice view representing the columns of the given row. The returned view is backed by this matrix, so changes in the returned view are reflected in this matrix, and vice-versa. To obtain a slice view on subranges, construct a sub-ranging view (viewPart(...)), then apply this method to the sub-range view.

        Example:

        2 x 3 matrix:
        1, 2, 3
        4, 5, 6
        viewRow(0) ==> Matrix1D of size 3:
        1, 2, 3
        Overrides:
        viewRow in class DoubleMatrix2D
        Parameters:
        row - the row to fix.
        Returns:
        a new slice view.
        Throws:
        java.lang.IndexOutOfBoundsException - if row < 0 || row >= rows().
        See Also:
        viewColumn(int)
      • viewRowFlip

        public DoubleMatrix2D viewRowFlip()
        Constructs and returns a new flip view along the row axis. What used to be row 0 is now row rows()-1, ..., what used to be row rows()-1 is now row 0. The returned view is backed by this matrix, so changes in the returned view are reflected in this matrix, and vice-versa.

        Example:

        2 x 3 matrix:
        1, 2, 3
        4, 5, 6
        rowFlip ==> 2 x 3 matrix:
        4, 5, 6
        1, 2, 3
        rowFlip ==> 2 x 3 matrix:
        1, 2, 3
        4, 5, 6
        Overrides:
        viewRowFlip in class DoubleMatrix2D
        Returns:
        a new flip view.
        See Also:
        viewColumnFlip()
      • viewSelection

        public DoubleMatrix2D viewSelection​(int[] rowIndexes,
                                            int[] columnIndexes)
        Constructs and returns a new selection view that is a matrix holding the indicated cells. There holds view.rows() == rowIndexes.length, view.columns() == columnIndexes.length and view.get(i,j) == this.get(rowIndexes[i],columnIndexes[j]). Indexes can occur multiple times and can be in arbitrary order.

        Example:

        this = 2 x 3 matrix:
        1, 2, 3
        4, 5, 6
        rowIndexes     = (0,1)
        columnIndexes  = (1,0,1,0)
        -->
        view = 2 x 4 matrix:
        2, 1, 2, 1
        5, 4, 5, 4
        
        Note that modifying the index arguments after this call has returned has no effect on the view. The returned view is backed by this matrix, so changes in the returned view are reflected in this matrix, and vice-versa.

        To indicate "all" rows or "all columns", simply set the respective parameter

        Overrides:
        viewSelection in class DoubleMatrix2D
        Parameters:
        rowIndexes - The rows of the cells that shall be visible in the new view. To indicate that all rows shall be visible, simply set this parameter to null.
        columnIndexes - The columns of the cells that shall be visible in the new view. To indicate that all columns shall be visible, simply set this parameter to null.
        Returns:
        the new view.
        Throws:
        java.lang.IndexOutOfBoundsException - if !(0 <= rowIndexes[i] < rows()) for any i=0..rowIndexes.length()-1.
        java.lang.IndexOutOfBoundsException - if !(0 <= columnIndexes[i] < columns()) for any i=0..columnIndexes.length()-1.
      • viewSelectionLike

        protected DoubleMatrix2D viewSelectionLike​(int[] rowOffsets,
                                                   int[] columnOffsets)
        Construct and returns a new selection view.
        Specified by:
        viewSelectionLike in class DoubleMatrix2D
        Parameters:
        rowOffsets - the offsets of the visible elements.
        columnOffsets - the offsets of the visible elements.
        Returns:
        a new view.
      • viewStrides

        public DoubleMatrix2D viewStrides​(int _rowStride,
                                          int _columnStride)
        Constructs and returns a new stride view which is a sub matrix consisting of every i-th cell. More specifically, the view has this.rows()/rowStride rows and this.columns()/columnStride columns holding cells this.get(i*rowStride,j*columnStride) for all i = 0..rows()/rowStride - 1, j = 0..columns()/columnStride - 1. The returned view is backed by this matrix, so changes in the returned view are reflected in this matrix, and vice-versa.
        Overrides:
        viewStrides in class DoubleMatrix2D
        Parameters:
        rowStride - the row step factor.
        columnStride - the column step factor.
        Returns:
        a new view.
        Throws:
        java.lang.IndexOutOfBoundsException - if rowStride<=0 || columnStride<=0.