Class Complex2D

java.lang.Object
ffx.numerics.fft.Complex2D
public class Complex2D extends Object
Compute the 2D FFT of complex, double precision input of arbitrary dimensions via 1D Mixed Radix FFTs.

For interleaved data, the location of the input point [x, y] within the input array must be:
double real = input[x*nextX + y*nextY]
double imag = input[x*nextX + y*nextY + im]
where
nextX = 2 nextY = 2*nX im = 1

For blocked data along x, the location of the input point [x, y] within the input array must be:
double real = input[x*nextX + y*nextY]
double imag = input[x*nextX + y*nextY + im]
where for BLOCKED_X
nextX = 1
nextY = 2*nX
im = nX
and for BLOCKED_XY
nextX = 1
nextY = nX
im = nX*nY

Since:
1.0
Author:
Michal J. Schnieders
See Also:

  • Constructor Summary

    Constructors
    Constructor
    Description
    Complex2D(int nX, int nY)
    Create a new 2D Complex FFT for interleaved data.
    Complex2D(int nX, int nY, DataLayout2D layout, int imOffset)
    Create a new 2D Complex FFT.

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    fft(double[] input, int index)
    Compute the 2D FFT.
    DataLayout2D
    getLayout()
    Get the Data Layout.
    void
    ifft(double[] input, int index)
    Compute the 2D IFFT.
    static double[]
    initRandomData(int dim, ParallelTeam parallelTeam)
    Initialize a 2D data for testing purposes.
    static void
    main(String[] args)
    Test the Complex2D FFT.
    void
    setPackFFTs(boolean packFFTs)
    Set the 2D transform to pack FFTs into a contiguous array to compute all FFTs at once.
    void
    setUseSIMD(boolean useSIMD)
    Set the 2D transform to use SIMD instructions.

    Methods inherited from class Object

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

  • Constructor Details

    • Complex2D

      public Complex2D(int nX, int nY)
      Create a new 2D Complex FFT for interleaved data.
      Parameters:
      nX - The number of points in the X dimension.
      nY - The number of points in the Y dimension.

    • Complex2D

      public Complex2D(int nX, int nY, DataLayout2D layout, int imOffset)
      Create a new 2D Complex FFT.
      Parameters:
      nX - The number of points in the X dimension.
      nY - The number of points in the Y dimension.
      layout - The data layout.
      imOffset - The offset between real and imaginary values.

  • Method Details

    • getLayout

      public DataLayout2D getLayout()
      Get the Data Layout.
      Returns:
      The layout.

    • setUseSIMD

      public void setUseSIMD(boolean useSIMD)
      Set the 2D transform to use SIMD instructions.
      Parameters:
      useSIMD - True to use SIMD instructions.

    • setPackFFTs

      public void setPackFFTs(boolean packFFTs)
      Set the 2D transform to pack FFTs into a contiguous array to compute all FFTs at once.
      Parameters:
      packFFTs - True to pack FFTs.

    • fft

      public void fft(double[] input, int index)
      Compute the 2D FFT.
      Parameters:
      input - The input array must be of size 2 * nX * nY.
      index - The offset into the input array of the first element.

    • ifft

      public void ifft(double[] input, int index)
      Compute the 2D IFFT.
      Parameters:
      input - The input array must be of size 2 * nX * nY.
      index - The offset into the input array of the first element.

    • main

      public static void main(String[] args) throws Exception
      Test the Complex2D FFT.
      Parameters:
      args - an array of String objects.
      Throws:
      Exception - if any.
      Since:
      1.0

    • initRandomData

      public static double[] initRandomData(int dim, ParallelTeam parallelTeam)
      Initialize a 2D data for testing purposes.
      Parameters:
      dim - The dimension of the 2D grid.
      Returns:
      The 3D data.
      Since:
      1.0