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