rfft2i - initialize the array WSAVE, which is used in both the forward and
backward transforms.
SUBROUTINE RFFT2I( M, N, WORK)
INTEGER M, N
REAL WORK(*)
SUBROUTINE RFFT2I_64( M, N, WORK)
INTEGER*8 M, N
REAL WORK(*)
SUBROUTINE FFT2I( M, N, WORK)
INTEGER :: M, N
REAL, DIMENSION(:) :: WORK
SUBROUTINE FFT2I_64( M, N, WORK)
INTEGER(8) :: M, N
REAL, DIMENSION(:) :: WORK
#include <sunperf.h>
void rfft2i(int m, int n, float *work);
void rfft2i_64(long m, long n, float *work);
- 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.
RFFT2I needs to be called only once to initialize array WORK before calling
RFFT2F and/or RFFT2B if M, N and WORK remain unchanged between these calls.
Thus, subsequent transforms or inverse transforms of same size can be obtained
faster than the first since they do not require initialization of the workspace.