Documentation of 'cern.colt.matrix.tfloat.impl.DenseFloatMatrix2D' Java class
DenseFloatMatrix2D
Skip navigation links
cern.colt.matrix.tfloat.impl

Class DenseFloatMatrix2D

  • All Implemented Interfaces:
    java.io.Serializable, java.lang.Cloneable

    public class DenseFloatMatrix2D
extends FloatMatrix2D
    Dense 2-d matrix holding float elements. First see the package summary and javadoc tree view to get the broad picture.

    Implementation:

    Internally holds one single contigous one-dimensional array, addressed in row major. Note that this implementation is not synchronized.

    Time complexity:

    O(1) (i.e. constant time) for the basic operations get, getQuick, set, setQuick and size,

    Cells are internally addressed in row-major. Applications demanding utmost speed can exploit this fact. Setting/getting values in a loop row-by-row is quicker than column-by-column. Thus 

     for (int row = 0; row < rows; row++) {
     for (int column = 0; column < columns; column++) {
         matrix.setQuick(row, column, someValue);
     }
 }
    is quicker than 
     for (int column = 0; column < columns; column++) {
     for (int row = 0; row < rows; row++) {
         matrix.setQuick(row, column, someValue);
     }
 }
    See Also:
    Serialized Form

    • Constructor Detail

      • DenseFloatMatrix2D

        public DenseFloatMatrix2D(float[][] values)
        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 .

      • DenseFloatMatrix2D

        public DenseFloatMatrix2D(int rows,
                          int columns)
        Constructs a matrix with a given number of rows and columns. All entries are initially 0.
        Parameters:
        rows - the number of rows the matrix shall have.
        columns - the number of columns the matrix shall have.
        Throws:
        java.lang.IllegalArgumentException - if rows<0 || columns<0 || (double)columns*rows > Integer.MAX_VALUE .

      • DenseFloatMatrix2D

        public DenseFloatMatrix2D(int rows,
                          int columns,
                          float[] elements,
                          int rowZero,
                          int columnZero,
                          int rowStride,
                          int columnStride,
                          boolean isView)
        Constructs a matrix with the given parameters.
        Parameters:
        rows - the number of rows the matrix shall have.
        columns - the number of columns the matrix shall have.
        elements - the cells.
        rowZero - the position of the first element.
        columnZero - the position of the first element.
        rowStride - the number of elements between two rows, i.e. index(i+1,j)-index(i,j).
        columnStride - the number of elements between two columns, i.e. index(i,j+1)-index(i,j).
        isView - if true then a matrix view is constructed
        Throws:
        java.lang.IllegalArgumentException - if rows<0 || columns<0 || (double)columns*rows > Integer.MAX_VALUE or flip's are illegal.

      • DenseFloatMatrix2D

        public DenseFloatMatrix2D(MatrixVectorReader reader)
                   throws java.io.IOException
        Constructs a matrix from MatrixVectorReader.
        Parameters:
        reader - matrix reader
        Throws:
        java.io.IOException

    • Method Detail

      • aggregate

        public float aggregate(FloatFloatFunction aggr,
                       FloatFunction f)
        Description copied from class: FloatMatrix2D
        Applies a function to each cell and aggregates the results. Returns a value v such that v==a(size()) where a(i) == aggr( a(i-1), f(get(row,column)) ) and terminators are a(1) == f(get(0,0)), a(0)==Float.NaN.

        Example: 

                 cern.jet.math.Functions F = cern.jet.math.Functions.functions;
         2 x 2 matrix
         0 1
         2 3
 
         // Sum( x[row,col]*x[row,col] ) 
         matrix.aggregate(F.plus,F.square);
         --> 14
        For further examples, see the package doc.
        Overrides:
        aggregate in class FloatMatrix2D
        Parameters:
        aggr - an aggregation function taking as first argument the current aggregation and as second argument the transformed current cell value.
        f - a function transforming the current cell value.
        Returns:
        the aggregated measure.
        See Also:
        FloatFunctions

      • aggregate

        public float aggregate(FloatFloatFunction aggr,
                       FloatFunction f,
                       FloatProcedure cond)
        Description copied from class: FloatMatrix2D
        Applies a function to each cell that satisfies a condition and aggregates the results.
        Overrides:
        aggregate in class FloatMatrix2D
        Parameters:
        aggr - an aggregation function taking as first argument the current aggregation and as second argument the transformed current cell value.
        f - a function transforming the current cell value.
        cond - a condition.
        Returns:
        the aggregated measure.
        See Also:
        FloatFunctions

      • aggregate

        public float aggregate(FloatFloatFunction aggr,
                       FloatFunction f,
                       IntArrayList rowList,
                       IntArrayList columnList)
        Description copied from class: FloatMatrix2D
        Applies a function to all cells with a given indexes and aggregates the results.
        Overrides:
        aggregate in class FloatMatrix2D
        Parameters:
        aggr - an aggregation function taking as first argument the current aggregation and as second argument the transformed current cell value.
        f - a function transforming the current cell value.
        rowList - row indexes.
        columnList - column indexes.
        Returns:
        the aggregated measure.
        See Also:
        FloatFunctions

      • aggregate

        public float aggregate(FloatMatrix2D other,
                       FloatFloatFunction aggr,
                       FloatFloatFunction f)
        Description copied from class: FloatMatrix2D
        Applies a function to each corresponding cell of two matrices and aggregates the results. Returns a value v such that v==a(size()) where a(i) == aggr( a(i-1), f(get(row,column),other.get(row,column)) ) and terminators are a(1) == f(get(0,0),other.get(0,0)), a(0)==Float.NaN.

        Example: 

                 cern.jet.math.Functions F = cern.jet.math.Functions.functions;
         x == 2 x 2 matrix
         0 1
         2 3
 
         y == 2 x 2 matrix
         0 1
         2 3
 
         // Sum( x[row,col] * y[row,col] ) 
         x.aggregate(y, F.plus, F.mult);
         --> 14
 
         // Sum( (x[row,col] + y[row,col])ˆ2 )
         x.aggregate(y, F.plus, F.chain(F.square,F.plus));
         --> 56
        For further examples, see the package doc.
        Overrides:
        aggregate in class FloatMatrix2D
        aggr - an aggregation function taking as first argument the current aggregation and as second argument the transformed current cell values.
        f - a function transforming the current cell values.
        Returns:
        the aggregated measure.
        See Also:
        FloatFunctions

      • assign

        public FloatMatrix2D assign(FloatFunction function)
        Description copied from class: FloatMatrix2D
        Assigns the result of a function to each cell; x[row,col] = function(x[row,col]).

        Example: 

                 matrix = 2 x 2 matrix 
         0.5 1.5      
         2.5 3.5
 
         // change each cell to its sine
         matrix.assign(cern.jet.math.Functions.sin);
         -->
         2 x 2 matrix
         0.479426  0.997495 
         0.598472 -0.350783
        For further examples, see the package doc.
        Overrides:
        assign in class FloatMatrix2D
        Parameters:
        function - a function object taking as argument the current cell's value.
        Returns:
        this (for convenience only).
        See Also:
        FloatFunctions

      • assign

        public FloatMatrix2D assign(FloatProcedure cond,
                            float value)
        Description copied from class: FloatMatrix2D
        Assigns a value to all cells that satisfy a condition.
        Overrides:
        assign in class FloatMatrix2D
        Parameters:
        cond - a condition.
        value - a value.
        Returns:
        this (for convenience only).

      • assign

        public FloatMatrix2D assign(float value)
        Description copied from class: FloatMatrix2D
        Sets all cells to the state specified by value.
        Overrides:
        assign in class FloatMatrix2D
        Parameters:
        value - the value to be filled into the cells.
        Returns:
        this (for convenience only).

      • assign

        public FloatMatrix2D assign(float[] values)
        Description copied from class: FloatMatrix2D
        Sets all cells to the state specified by values. values is required to have the form values[row*column] and elements have to be stored in a row-wise order.

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

        Overrides:
        assign in class FloatMatrix2D
        Parameters:
        values - the values to be filled into the cells.
        Returns:
        this (for convenience only).

      • assign

        public FloatMatrix2D assign(float[][] values)
        Description copied from class: FloatMatrix2D
        Sets all cells to the state specified by values. values is required to have the form values[row][column] and have exactly the same number of rows and columns as the receiver.

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

        Overrides:
        assign in class FloatMatrix2D
        Parameters:
        values - the values to be filled into the cells.
        Returns:
        this (for convenience only).

      • assign

        public FloatMatrix2D assign(FloatMatrix2D source)
        Description copied from class: FloatMatrix2D
        Replaces all cell values of the receiver with the values of another matrix. Both matrices must have the same number of rows and columns. If both matrices share the same cells (as is the case if they are views derived from the same matrix) and intersect in an ambiguous way, then replaces as if using an intermediate auxiliary deep copy of other.
        Overrides:
        assign in class FloatMatrix2D
        Parameters:
        source - the source matrix to copy from (may be identical to the receiver).
        Returns:
        this (for convenience only).

      • assign

        public FloatMatrix2D assign(FloatMatrix2D y,
                            FloatFloatFunction function)
        Description copied from class: FloatMatrix2D
        Assigns the result of a function to each cell; x[row,col] = function(x[row,col],y[row,col]).

        Example: 

                 // assign x[row,col] = x[row,col]<sup>y[row,col]</sup>
         m1 = 2 x 2 matrix 
         0 1 
         2 3
 
         m2 = 2 x 2 matrix 
         0 2 
         4 6
 
         m1.assign(m2, cern.jet.math.Functions.pow);
         -->
         m1 == 2 x 2 matrix
         1   1 
         16 729
        For further examples, see the package doc.
        Overrides:
        assign in class FloatMatrix2D
        Parameters:
        y - the secondary matrix to operate on.
        function - a function object taking as first argument the current cell's value of this, and as second argument the current cell's value of y,
        Returns:
        this (for convenience only).
        See Also:
        FloatFunctions

      • assign

        public FloatMatrix2D assign(FloatMatrix2D y,
                            FloatFloatFunction function,
                            IntArrayList rowList,
                            IntArrayList columnList)
        Description copied from class: FloatMatrix2D
        Assigns the result of a function to all cells with a given indexes
        Overrides:
        assign in class FloatMatrix2D
        Parameters:
        y - the secondary matrix to operate on.
        function - a function object taking as first argument the current cell's value of this, and as second argument the current cell's value of y,
        rowList - row indexes.
        columnList - column indexes.
        Returns:
        this (for convenience only).
        See Also:
        FloatFunctions

      • cardinality

        public int cardinality()
        Description copied from class: FloatMatrix2D
        Returns the number of cells having non-zero values; ignores tolerance.
        Overrides:
        cardinality in class FloatMatrix2D
        Returns:
        cardinality

      • dct2

        public void dct2(boolean scale)
        Computes the 2D discrete cosine transform (DCT-II) of this matrix.
        Parameters:
        scale - if true then scaling is performed

      • dctColumns

        public void dctColumns(boolean scale)
        Computes the discrete cosine transform (DCT-II) of each column of this matrix.
        Parameters:
        scale - if true then scaling is performed

      • dctRows

        public void dctRows(boolean scale)
        Computes the discrete cosine transform (DCT-II) of each row of this matrix.
        Parameters:
        scale - if true then scaling is performed

      • dht2

        public void dht2()
        Computes the 2D discrete Hartley transform (DHT) of this matrix.

      • dhtColumns

        public void dhtColumns()
        Computes the discrete Hartley transform (DHT) of each column of this matrix.

      • dhtRows

        public void dhtRows()
        Computes the discrete Hartley transform (DHT) of each row of this matrix.

      • dst2

        public void dst2(boolean scale)
        Computes the 2D discrete sine transform (DST-II) of this matrix.
        Parameters:
        scale - if true then scaling is performed

      • dstColumns

        public void dstColumns(boolean scale)
        Computes the discrete sine transform (DST-II) of each column of this matrix.
        Parameters:
        scale - if true then scaling is performed

      • dstRows

        public void dstRows(boolean scale)
        Computes the discrete sine transform (DST-II) of each row of this matrix.
        Parameters:
        scale - if true then scaling is performed

      • elements

        public float[] elements()
        Description copied from class: FloatMatrix2D
        Returns the elements of this matrix.
        Specified by:
        elements in class FloatMatrix2D
        Returns:
        the elements

      • fft2

        public void fft2()
        Computes the 2D discrete Fourier transform (DFT) of this matrix. The physical layout of the output data is as follows: 
         this[k1][2*k2] = Re[k1][k2] = Re[rows-k1][columns-k2], 
 this[k1][2*k2+1] = Im[k1][k2] = -Im[rows-k1][columns-k2], 
       0<k1<rows, 0<k2<columns/2, 
 this[0][2*k2] = Re[0][k2] = Re[0][columns-k2], 
 this[0][2*k2+1] = Im[0][k2] = -Im[0][columns-k2], 
       0<k2<columns/2, 
 this[k1][0] = Re[k1][0] = Re[rows-k1][0], 
 this[k1][1] = Im[k1][0] = -Im[rows-k1][0], 
 this[rows-k1][1] = Re[k1][columns/2] = Re[rows-k1][columns/2], 
 this[rows-k1][0] = -Im[k1][columns/2] = Im[rows-k1][columns/2], 
       0<k1<rows/2, 
 this[0][0] = Re[0][0], 
 this[0][1] = Re[0][columns/2], 
 this[rows/2][0] = Re[rows/2][0], 
 this[rows/2][1] = Re[rows/2][columns/2]
        This method computes only half of the elements of the real transform. The other half satisfies the symmetry condition. If you want the full real forward transform, use getFft2. To get back the original data, use ifft2.
        Throws:
        java.lang.IllegalArgumentException - if the row size or the column size of this matrix is not a power of 2 number.

      • forEachNonZero

        public FloatMatrix2D forEachNonZero(IntIntFloatFunction function)
        Description copied from class: FloatMatrix2D
        Assigns the result of a function to each non-zero cell; x[row,col] = function(x[row,col]). Use this method for fast special-purpose iteration. If you want to modify another matrix instead of this (i.e. work in read-only mode), simply return the input value unchanged. Parameters to function are as follows: first==row, second==column, third==nonZeroValue.
        Overrides:
        forEachNonZero in class FloatMatrix2D
        Parameters:
        function - a function object taking as argument the current non-zero cell's row, column and value.
        Returns:
        this (for convenience only).

      • getColumnMajor

        public DenseColumnFloatMatrix2D getColumnMajor()
        Returns a new matrix that has the same elements as this matrix, but they are addressed internally in column major. This method creates a new object (not a view), so changes in the returned matrix are NOT reflected in this matrix.
        Returns:
        this matrix with elements addressed internally in column major

      • getFft2

        public DenseFComplexMatrix2D getFft2()
        Returns new complex matrix which is the 2D discrete Fourier transform (DFT) of this matrix.
        Returns:
        the 2D discrete Fourier transform (DFT) of this matrix.

      • getFftColumns

        public DenseFComplexMatrix2D getFftColumns()
        Returns new complex matrix which is the discrete Fourier transform (DFT) of each column of this matrix.
        Returns:
        the discrete Fourier transform (DFT) of each column of this matrix.

      • getFftRows

        public DenseFComplexMatrix2D getFftRows()
        Returns new complex matrix which is the discrete Fourier transform (DFT) of each row of this matrix.
        Returns:
        the discrete Fourier transform (DFT) of each row of this matrix.

      • getIfft2

        public DenseFComplexMatrix2D getIfft2(boolean scale)
        Returns new complex matrix which is the 2D inverse of the discrete Fourier transform (IDFT) of this matrix.
        Returns:
        the 2D inverse of the discrete Fourier transform (IDFT) of this matrix.

      • getIfftColumns

        public DenseFComplexMatrix2D getIfftColumns(boolean scale)
        Returns new complex matrix which is the inverse of the discrete Fourier transform (IDFT) of each column of this matrix.
        Returns:
        the inverse of the discrete Fourier transform (IDFT) of each column of this matrix.

      • getIfftRows

        public DenseFComplexMatrix2D getIfftRows(boolean scale)
        Returns new complex matrix which is the inverse of the discrete Fourier transform (IDFT) of each row of this matrix.
        Returns:
        the inverse of the discrete Fourier transform (IDFT) of each row of this matrix.

      • getMaxLocation

        public float[] getMaxLocation()
        Description copied from class: FloatMatrix2D
        Return the maximum value of this matrix together with its location
        Overrides:
        getMaxLocation in class FloatMatrix2D
        Returns:
        maximum_value, row_location, column_location };

      • getMinLocation

        public float[] getMinLocation()
        Description copied from class: FloatMatrix2D
        Return the minimum value of this matrix together with its location
        Overrides:
        getMinLocation in class FloatMatrix2D
        Returns:
        minimum_value, row_location, column_location};

      • getNegativeValues

        public void getNegativeValues(IntArrayList rowList,
                              IntArrayList columnList,
                              FloatArrayList valueList)
        Description copied from class: FloatMatrix2D
        Fills the coordinates and values of cells having negative values into the specified lists. Fills into the lists, starting at index 0. After this call returns the specified lists all have a new size, the number of non-zero values.
        Overrides:
        getNegativeValues in class FloatMatrix2D
        Parameters:
        rowList - the list to be filled with row indexes, can have any size.
        columnList - the list to be filled with column indexes, can have any size.
        valueList - the list to be filled with values, can have any size.

      • getNonZeros

        public void getNonZeros(IntArrayList rowList,
                        IntArrayList columnList,
                        FloatArrayList valueList)
        Description copied from class: FloatMatrix2D
        Fills the coordinates and values of cells having non-zero values into the specified lists. Fills into the lists, starting at index 0. After this call returns the specified lists all have a new size, the number of non-zero values.

        In general, fill order is unspecified. This implementation fills like for (row = 0..rows-1) for (column = 0..columns-1) do ... . However, subclasses are free to us any other order, even an order that may change over time as cell values are changed. (Of course, result lists indexes are guaranteed to correspond to the same cell).

        Example: 

                 2 x 3 matrix:
         0, 0, 8
         0, 7, 0
         -->
         rowList    = (0,1)
         columnList = (2,1)
         valueList  = (8,7)
        In other words, get(0,2)==8, get(1,1)==7.
        Overrides:
        getNonZeros in class FloatMatrix2D
        Parameters:
        rowList - the list to be filled with row indexes, can have any size.
        columnList - the list to be filled with column indexes, can have any size.
        valueList - the list to be filled with values, can have any size.

      • getPositiveValues

        public void getPositiveValues(IntArrayList rowList,
                              IntArrayList columnList,
                              FloatArrayList valueList)
        Description copied from class: FloatMatrix2D
        Fills the coordinates and values of cells having positive values into the specified lists. Fills into the lists, starting at index 0. After this call returns the specified lists all have a new size, the number of non-zero values.
        Overrides:
        getPositiveValues in class FloatMatrix2D
        Parameters:
        rowList - the list to be filled with row indexes, can have any size.
        columnList - the list to be filled with column indexes, can have any size.
        valueList - the list to be filled with values, can have any size.

      • getQuick

        public float getQuick(int row,
                      int column)
        Description copied from class: FloatMatrix2D
        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 FloatMatrix2D
        Parameters:
        row - the index of the row-coordinate.
        column - the index of the column-coordinate.
        Returns:
        the value at the specified coordinate.

      • idct2

        public void idct2(boolean scale)
        Computes the 2D inverse of the discrete cosine transform (DCT-III) of this matrix.
        Parameters:
        scale - if true then scaling is performed

      • idctColumns

        public void idctColumns(boolean scale)
        Computes the inverse of the discrete cosine transform (DCT-III) of each column of this matrix.
        Parameters:
        scale - if true then scaling is performed

      • idctRows

        public void idctRows(boolean scale)
        Computes the inverse of the discrete cosine transform (DCT-III) of each row of this matrix.
        Parameters:
        scale - if true then scaling is performed

      • idht2

        public void idht2(boolean scale)
        Computes the 2D inverse of the discrete Hartley transform (IDHT) of this matrix.
        Parameters:
        scale - if true then scaling is performed

      • idhtColumns

        public void idhtColumns(boolean scale)
        Computes the inverse of the discrete Hartley transform (IDHT) of each column of this matrix.
        Parameters:
        scale - if true then scaling is performed

      • idhtRows

        public void idhtRows(boolean scale)
        Computes the inverse of the discrete Hartley transform (IDHT) of each row of this matrix.
        Parameters:
        scale - if true then scaling is performed

      • idst2

        public void idst2(boolean scale)
        Computes the 2D inverse of the discrete sine transform (DST-III) of this matrix.
        Parameters:
        scale - if true then scaling is performed

      • idstColumns

        public void idstColumns(boolean scale)
        Computes the inverse of the discrete sine transform (DST-III) of each column of this matrix.
        Parameters:
        scale - if true then scaling is performed

      • idstRows

        public void idstRows(boolean scale)
        Computes the inverse of the discrete sine transform (DST-III) of each row of this matrix.
        Parameters:
        scale - if true then scaling is performed

      • ifft2

        public void ifft2(boolean scale)
        Computes the 2D inverse of the discrete Fourier transform (IDFT) of this matrix. The physical layout of the input data has to be as follows: 
         this[k1][2*k2] = Re[k1][k2] = Re[rows-k1][columns-k2], 
 this[k1][2*k2+1] = Im[k1][k2] = -Im[rows-k1][columns-k2], 
       0<k1<rows, 0<k2<columns/2, 
 this[0][2*k2] = Re[0][k2] = Re[0][columns-k2], 
 this[0][2*k2+1] = Im[0][k2] = -Im[0][columns-k2], 
       0<k2<columns/2, 
 this[k1][0] = Re[k1][0] = Re[rows-k1][0], 
 this[k1][1] = Im[k1][0] = -Im[rows-k1][0], 
 this[rows-k1][1] = Re[k1][columns/2] = Re[rows-k1][columns/2], 
 this[rows-k1][0] = -Im[k1][columns/2] = Im[rows-k1][columns/2], 
       0<k1<rows/2, 
 this[0][0] = Re[0][0], 
 this[0][1] = Re[0][columns/2], 
 this[rows/2][0] = Re[rows/2][0], 
 this[rows/2][1] = Re[rows/2][columns/2]
        This method computes only half of the elements of the real transform. The other half satisfies the symmetry condition. If you want the full real inverse transform, use getIfft2.
        Parameters:
        scale - if true then scaling is performed
        Throws:
        java.lang.IllegalArgumentException - if the row size or the column size of this matrix is not a power of 2 number.

      • index

        public long index(int row,
                  int column)
        Description copied from class: AbstractMatrix2D
        Returns the position of the given coordinate within the (virtual or non-virtual) internal 1-dimensional array.
        Overrides:
        index in class AbstractMatrix2D
        Parameters:
        row - the index of the row-coordinate.
        column - the index of the column-coordinate.

      • like

        public FloatMatrix2D like(int rows,
                          int columns)
        Description copied from class: FloatMatrix2D
        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 DenseFloatMatrix2D the new matrix must also be of type DenseFloatMatrix2D, if the receiver is an instance of type SparseFloatMatrix2D the new matrix must also be of type SparseFloatMatrix2D, etc. In general, the new matrix should have internal parametrization as similar as possible.
        Specified by:
        like in class FloatMatrix2D
        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 FloatMatrix1D like1D(int size)
        Description copied from class: FloatMatrix2D
        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 DenseFloatMatrix2D the new matrix must be of type DenseFloatMatrix1D, if the receiver is an instance of type SparseFloatMatrix2D the new matrix must be of type SparseFloatMatrix1D, etc.
        Specified by:
        like1D in class FloatMatrix2D
        Parameters:
        size - the number of cells the matrix shall have.
        Returns:
        a new matrix of the corresponding dynamic type.

      • setQuick

        public void setQuick(int row,
                     int column,
                     float value)
        Description copied from class: FloatMatrix2D
        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 FloatMatrix2D
        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.

      • toArray

        public float[][] toArray()
        Description copied from class: FloatMatrix2D
        Constructs and returns a 2-dimensional array containing the cell values. The returned array values has the form values[row][column] and has the same number of rows and columns as the receiver.

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

        Overrides:
        toArray in class FloatMatrix2D
        Returns:
        an array filled with the values of the cells.

      • vectorize

        public FloatMatrix1D vectorize()
        Description copied from class: FloatMatrix2D
        Returns a vector obtained by stacking the columns of the matrix on top of one another.
        Specified by:
        vectorize in class FloatMatrix2D
        Returns:
        a vector of columns of this matrix.

      • zAssign8Neighbors

        public void zAssign8Neighbors(FloatMatrix2D B,
                              Float9Function function)
        Description copied from class: FloatMatrix2D
        8 neighbor stencil transformation. For efficient finite difference operations. Applies a function to a moving 3 x 3 window. Does nothing if rows() < 3 || columns() < 3. 
                 B[i,j] = function.apply(
            A[i-1,j-1], A[i-1,j], A[i-1,j+1],
            A[i,  j-1], A[i,  j], A[i,  j+1],
            A[i+1,j-1], A[i+1,j], A[i+1,j+1]
            )
 
         x x x -     - x x x     - - - - 
         x o x -     - x o x     - - - - 
         x x x -     - x x x ... - x x x 
         - - - -     - - - -     - x o x 
         - - - -     - - - -     - x x x
        Make sure that cells of this and B do not overlap. In case of overlapping views, behaviour is unspecified.

        Example: 

         
 final float alpha = 0.25; final float beta = 0.75; // 8 neighbors
 cern.colt.function.Float9Function f = new
 cern.colt.function.Float9Function() {    public final
 float apply(       float a00, float a01,
 float a02,       float a10, float a11,
 float a12,       float a20, float a21,
 float a22) {
          return beta*a11 +
 alpha*(a00+a01+a02 + a10+a12 + a20+a21+a22);
       } }; A.zAssign8Neighbors(B,f); // 4
 neighbors cern.colt.function.Float9Function g = new
 cern.colt.function.Float9Function() {    public final
 float apply(       float a00, float a01,
 float a02,       float a10, float a11,
 float a12,       float a20, float a21,
 float a22) {       return beta*a11 +
 alpha*(a01+a10+a12+a21);    } C.zAssign8Neighbors(B,g); //
 fast, even though it doesn't look like it };
        Overrides:
        zAssign8Neighbors in class FloatMatrix2D
        Parameters:
        B - the matrix to hold the results.
        function - the function to be applied to the 9 cells.

      • zMult

        public FloatMatrix1D zMult(FloatMatrix1D y,
                           FloatMatrix1D z,
                           float alpha,
                           float beta,
                           boolean transposeA)
        Description copied from class: FloatMatrix2D
        Linear algebraic matrix-vector multiplication; z = alpha * A * y + beta*z. z[i] = alpha*Sum(A[i,j] * y[j]) + beta*z[i], i=0..A.rows()-1, j=0..y.size()-1 . Where A == this.
        Note: Matrix shape conformance is checked after potential transpositions.
        Overrides:
        zMult in class FloatMatrix2D
        Parameters:
        y - the source vector.
        z - the vector where results are to be stored. Set this parameter to null to indicate that a new result vector shall be constructed.
        Returns:
        z (for convenience only).

      • zMult

        public FloatMatrix2D zMult(FloatMatrix2D B,
                           FloatMatrix2D C,
                           float alpha,
                           float beta,
                           boolean transposeA,
                           boolean transposeB)
        Description copied from class: FloatMatrix2D
        Linear algebraic matrix-matrix multiplication; C = alpha * A x B + beta*C. C[i,j] = alpha*Sum(A[i,k] * B[k,j]) + beta*C[i,j], k=0..n-1.
        Matrix shapes: A(m x n), B(n x p), C(m x p).
        Note: Matrix shape conformance is checked after potential transpositions.
        Overrides:
        zMult in class FloatMatrix2D
        Parameters:
        B - the second source matrix.
        C - the matrix where results are to be stored. Set this parameter to null to indicate that a new result matrix shall be constructed.
        Returns:
        C (for convenience only).

      • zSum

        public float zSum()
        Description copied from class: FloatMatrix2D
        Returns the sum of all cells; Sum( x[i,j] ).
        Overrides:
        zSum in class FloatMatrix2D
        Returns:
        the sum.
Skip navigation links

DMelt 3.0 © DataMelt by jWork.ORG

You see the box below because you did not login.