dfft2i (3p)

Name

dfft2i - initialize the array WSAVE, which is used in both the forward and backward transforms.

Synopsis

SUBROUTINE DFFT2I(M, N, WORK)

INTEGER M, N
DOUBLE PRECISION WORK(*)

SUBROUTINE DFFT2I_64(M, N, WORK)

INTEGER*8 M, N
DOUBLE PRECISION WORK(*)




F95 INTERFACE
SUBROUTINE FFT2I(M, N, WORK)

INTEGER :: M, N
REAL(8), DIMENSION(:) :: WORK

SUBROUTINE FFT2I_64(M, N, WORK)

INTEGER(8) :: M, N
REAL(8), DIMENSION(:) :: WORK




C INTERFACE
#include <sunperf.h>

void dfft2i(int m, int n, double *work);

void dfft2i_64(long m, long n, double *work);

Description

Oracle Solaris Studio Performance Library                           dfft2i(3P)



NAME
       dfft2i  - initialize the array WSAVE, which is used in both the forward
       and backward transforms.


SYNOPSIS
       SUBROUTINE DFFT2I(M, N, WORK)

       INTEGER M, N
       DOUBLE PRECISION WORK(*)

       SUBROUTINE DFFT2I_64(M, N, WORK)

       INTEGER*8 M, N
       DOUBLE PRECISION WORK(*)




   F95 INTERFACE
       SUBROUTINE FFT2I(M, N, WORK)

       INTEGER :: M, N
       REAL(8), DIMENSION(:) :: WORK

       SUBROUTINE FFT2I_64(M, N, WORK)

       INTEGER(8) :: M, N
       REAL(8), DIMENSION(:) :: WORK




   C INTERFACE
       #include <sunperf.h>

       void dfft2i(int m, int n, double *work);

       void dfft2i_64(long m, long n, double *work);



ARGUMENTS
       M (input) Number of rows to be transformed.  M >= 0.


       N (input) Number of columns to be transformed.  N >= 0.


       WORK (input/output)
                 On entry, an array of dimension (M + 2*N + MAX(M, 2*N) +  30)
                 or  greater.  DFFT2I needs to be called only once to initial-
                 ize array WORK before calling DFFT2F and/or DFFT2B  if  M,  N
                 and  WORK remain unchanged between these calls.  Thus, subse-
                 quent transforms or inverse transforms of same  size  can  be
                 obtained faster than the first since they do not require ini-
                 tialization of the workspace.




                                  7 Nov 2015                        dfft2i(3P)