Package org.apache.sysds.runtime.matrix.data

Class LibMatrixFourier

java.lang.Object

org.apache.sysds.runtime.matrix.data.LibMatrixFourier

public class LibMatrixFourier
extends Object

Constructor Summary

Constructors

Constructor	Description
LibMatrixFourier()

Method Summary

Modifier and Type	Method	Description
static void	fft(double[] re, double[] im, int rows, int cols, int threads, boolean inclColCalc)	Function to perform FFT for two given double arrays.
static MatrixBlock[]	fft(MatrixBlock re, int threads)	Function to perform FFT for a given matrix.
static MatrixBlock[]	fft(MatrixBlock re, MatrixBlock im, int threads)	Function to perform FFT for two given matrices.
static MatrixBlock[]	fft_linearized(MatrixBlock re, int threads)	Function to perform FFT for each row of a given matrix.
static MatrixBlock[]	fft_linearized(MatrixBlock re, MatrixBlock im, int threads)	Function to perform FFT for each row of two given matrices.
static void	fft_one_dim(double[] re, double[] im, double[] re_inter, double[] im_inter, int start, int stop, int num, int minStep)	Function to perform one-dimensional FFT for two given double arrays.
static void	ifft(double[] re, double[] im, int rows, int cols, int threads, boolean inclColCalc)	Function to perform IFFT for two given double arrays.
static MatrixBlock[]	ifft(MatrixBlock re, int threads)	Function to perform IFFT for a given matrix.
static MatrixBlock[]	ifft(MatrixBlock re, MatrixBlock im, int threads)	Function to perform IFFT for two given matrices.
static MatrixBlock[]	ifft_linearized(MatrixBlock re, int threads)	Function to perform IFFT for each row of a given matrix.
static MatrixBlock[]	ifft_linearized(MatrixBlock re, MatrixBlock im, int threads)	Function to perform IFFT for each row of two given matrices.
static boolean	isPowerOfTwo(int n)	Function for checking whether the given integer is a power of two.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

LibMatrixFourier

public LibMatrixFourier()

Method Detail

fft

public static MatrixBlock[] fft(MatrixBlock re,
                                MatrixBlock im,
                                int threads)

Function to perform FFT for two given matrices. The first one represents the real values and the second one the imaginary values. The output also contains one matrix for the real and one for the imaginary values.

Parameters:

re - matrix object representing the real values

im - matrix object representing the imaginary values

threads - number of threads

Returns:

array of two matrix blocks

ifft

public static MatrixBlock[] ifft(MatrixBlock re,
                                 MatrixBlock im,
                                 int threads)

Function to perform IFFT for two given matrices. The first one represents the real values and the second one the imaginary values. The output also contains one matrix for the real and one for the imaginary values.

Parameters:

re - matrix object representing the real values

im - matrix object representing the imaginary values

threads - number of threads

Returns:

array of two matrix blocks

fft_linearized

public static MatrixBlock[] fft_linearized(MatrixBlock re,
                                           MatrixBlock im,
                                           int threads)

Function to perform FFT for each row of two given matrices. The first one represents the real values and the second one the imaginary values. The output also contains one matrix for the real and one for the imaginary values.

Parameters:

re - matrix object representing the real values

im - matrix object representing the imaginary values

threads - number of threads

Returns:

array of two matrix blocks

ifft_linearized

public static MatrixBlock[] ifft_linearized(MatrixBlock re,
                                            MatrixBlock im,
                                            int threads)

Function to perform IFFT for each row of two given matrices. The first one represents the real values and the second one the imaginary values. The output also contains one matrix for the real and one for the imaginary values.

Parameters:

re - matrix object representing the real values

im - matrix object representing the imaginary values

threads - number of threads

Returns:

array of two matrix blocks

fft

public static void fft(double[] re,
                       double[] im,
                       int rows,
                       int cols,
                       int threads,
                       boolean inclColCalc)

Function to perform FFT for two given double arrays. The first one represents the real values and the second one the imaginary values. Both arrays get updated and contain the result.

Parameters:

re - array representing the real values

im - array representing the imaginary values

rows - number of rows

cols - number of rows

threads - number of threads

inclColCalc - if true, fft is also calculated for each column, otherwise only for each row

ifft

public static void ifft(double[] re,
                        double[] im,
                        int rows,
                        int cols,
                        int threads,
                        boolean inclColCalc)

Function to perform IFFT for two given double arrays. The first one represents the real values and the second one the imaginary values. Both arrays get updated and contain the result.

Parameters:

re - array representing the real values

im - array representing the imaginary values

rows - number of rows

cols - number of rows

threads - number of threads

inclColCalc - if true, fft is also calculated for each column, otherwise only for each row

fft_one_dim

public static void fft_one_dim(double[] re,
                               double[] im,
                               double[] re_inter,
                               double[] im_inter,
                               int start,
                               int stop,
                               int num,
                               int minStep)

Function to perform one-dimensional FFT for two given double arrays. The first one represents the real values and the second one the imaginary values. Both arrays get updated and contain the result.

Parameters:

re - array representing the real values

im - array representing the imaginary values

re_inter - array for the real values of intermediate results

im_inter - array for the imaginary values of intermediate results

start - start index (incl.)

stop - stop index (excl.)

num - number of values used for fft

minStep - step size between values used for fft

isPowerOfTwo

public static boolean isPowerOfTwo(int n)

Function for checking whether the given integer is a power of two.

Parameters:

n - integer to check

Returns:

true if n is a power of two, false otherwise

fft

public static MatrixBlock[] fft(MatrixBlock re,
                                int threads)

Function to perform FFT for a given matrix. The given matrix only represents real values. The output contains one matrix for the real and one for the imaginary values.

Parameters:

re - matrix object representing the real values

threads - number of threads

Returns:

array of two matrix blocks

ifft

public static MatrixBlock[] ifft(MatrixBlock re,
                                 int threads)

Function to perform IFFT for a given matrix. The given matrix only represents real values. The output contains one matrix for the real and one for the imaginary values.

Parameters:

re - matrix object representing the real values

threads - number of threads

Returns:

array of two matrix blocks

fft_linearized

public static MatrixBlock[] fft_linearized(MatrixBlock re,
                                           int threads)

Function to perform FFT for each row of a given matrix. The given matrix only represents real values. The output contains one matrix for the real and one for the imaginary values.

Parameters:

re - matrix object representing the real values

threads - number of threads

Returns:

array of two matrix blocks

ifft_linearized

public static MatrixBlock[] ifft_linearized(MatrixBlock re,
                                            int threads)

Function to perform IFFT for each row of a given matrix. The given matrix only represents real values. The output contains one matrix for the real and one for the imaginary values.

Parameters:

re - matrix object representing the real values

threads - number of threads

Returns:

array of two matrix blocks