vrfftb - compute a periodic sequence from its Fourier coefficients. The VRFFT operations are normalized, so a call of VRFFTF followed by a call of VRFFTB will return the original sequence.
SUBROUTINE VRFFTB(M, N, X, XT, MDIMX, WSAVE) INTEGER M, N, MDIMX REAL X(MDIMX,*), XT(MDIMX,*), WSAVE(*) SUBROUTINE VRFFTB_64(M, N, X, XT, MDIMX, WSAVE) INTEGER*8 M, N, MDIMX REAL X(MDIMX,*), XT(MDIMX,*), WSAVE(*) F95 INTERFACE SUBROUTINE FFTB(M, N, X, XT, MDIMX, WSAVE) INTEGER :: M, N, MDIMX REAL, DIMENSION(:) :: WSAVE REAL, DIMENSION(:,:) :: X, XT SUBROUTINE FFTB_64(M, N, X, XT, MDIMX, WSAVE) INTEGER(8) :: M, N, MDIMX REAL, DIMENSION(:) :: WSAVE REAL, DIMENSION(:,:) :: X, XT C INTERFACE #include <sunperf.h> void vrfftb(int m, int n, float *x, float *xt, int mdimx, float *wsave); void vrfftb_64(long m, long n, float *x, float *xt, long mdimx, float *wsave);
Oracle Solaris Studio Performance Library vrfftb(3P) NAME vrfftb - compute a periodic sequence from its Fourier coefficients. The VRFFT operations are normalized, so a call of VRFFTF followed by a call of VRFFTB will return the original sequence. SYNOPSIS SUBROUTINE VRFFTB(M, N, X, XT, MDIMX, WSAVE) INTEGER M, N, MDIMX REAL X(MDIMX,*), XT(MDIMX,*), WSAVE(*) SUBROUTINE VRFFTB_64(M, N, X, XT, MDIMX, WSAVE) INTEGER*8 M, N, MDIMX REAL X(MDIMX,*), XT(MDIMX,*), WSAVE(*) F95 INTERFACE SUBROUTINE FFTB(M, N, X, XT, MDIMX, WSAVE) INTEGER :: M, N, MDIMX REAL, DIMENSION(:) :: WSAVE REAL, DIMENSION(:,:) :: X, XT SUBROUTINE FFTB_64(M, N, X, XT, MDIMX, WSAVE) INTEGER(8) :: M, N, MDIMX REAL, DIMENSION(:) :: WSAVE REAL, DIMENSION(:,:) :: X, XT C INTERFACE #include <sunperf.h> void vrfftb(int m, int n, float *x, float *xt, int mdimx, float *wsave); void vrfftb_64(long m, long n, float *x, float *xt, long mdimx, float *wsave); ARGUMENTS M (input) The number of sequences to be transformed. M >= 0. N (input) Length of the sequence to be transformed. These subroutines are most efficient when N is a product of small primes. N >= 0. X (input/output) On entry, an array of length N containing the sequence to be transformed. For VRFFTF, a real two-dimensional array X(M,N) whose rows contain the sequences to be transformed. XT (workspace) A real two-dimensional work array with dimensions of (MDIMX x N). MDIMX (input) Leading dimension of the arrays X and XT as specified in a dimension or type statement. MDIMX >= M. WSAVE (input) On entry, an array of dimension (N+15) or greater initialized by VRFFTI. 7 Nov 2015 vrfftb(3P)