rfftb - compute a periodic sequence from its Fourier coefficients. The RFFT operations are unnormalized, so a call of RFFTF followed by a call of RFFTB will multiply the input sequence by N.
SUBROUTINE RFFTB(N, X, WSAVE) INTEGER N REAL X(*), WSAVE(*) SUBROUTINE RFFTB_64(N, X, WSAVE) INTEGER*8 N REAL X(*), WSAVE(*) F95 INTERFACE SUBROUTINE FFTB(N, X, WSAVE) INTEGER :: N REAL, DIMENSION(:) :: X, WSAVE SUBROUTINE FFTB_64(N, X, WSAVE) INTEGER(8) :: N REAL, DIMENSION(:) :: X, WSAVE C INTERFACE #include <sunperf.h> void rfftb(int n, float *x, float *wsave); void rfftb_64(long n, float *x, float *wsave);
Oracle Solaris Studio Performance Library rfftb(3P) NAME rfftb - compute a periodic sequence from its Fourier coefficients. The RFFT operations are unnormalized, so a call of RFFTF followed by a call of RFFTB will multiply the input sequence by N. SYNOPSIS SUBROUTINE RFFTB(N, X, WSAVE) INTEGER N REAL X(*), WSAVE(*) SUBROUTINE RFFTB_64(N, X, WSAVE) INTEGER*8 N REAL X(*), WSAVE(*) F95 INTERFACE SUBROUTINE FFTB(N, X, WSAVE) INTEGER :: N REAL, DIMENSION(:) :: X, WSAVE SUBROUTINE FFTB_64(N, X, WSAVE) INTEGER(8) :: N REAL, DIMENSION(:) :: X, WSAVE C INTERFACE #include <sunperf.h> void rfftb(int n, float *x, float *wsave); void rfftb_64(long n, float *x, float *wsave); ARGUMENTS 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. WSAVE (input/output) On entry, WSAVE must be an array of dimension (2 * N + 15) or greater and must have been initialized by RFFTI. 7 Nov 2015 rfftb(3P)