zfft2b - compute a periodic sequence from its Fourier coefficients. The FFT operations are unnormalized, so a call of ZFFT2F followed by a call of ZFFT2B will multiply the input sequence by M*N.
SUBROUTINE ZFFT2B(M, N, A, LDA, WORK, LWORK) DOUBLE COMPLEX A(LDA,*) INTEGER M, N, LDA, LWORK DOUBLE PRECISION WORK(*) SUBROUTINE ZFFT2B_64(M, N, A, LDA, WORK, LWORK) DOUBLE COMPLEX A(LDA,*) INTEGER*8 M, N, LDA, LWORK DOUBLE PRECISION WORK(*) F95 INTERFACE SUBROUTINE FFT2B(M, N, A, LDA, WORK, LWORK) COMPLEX(8), DIMENSION(:,:) :: A INTEGER :: M, N, LDA, LWORK REAL(8), DIMENSION(:) :: WORK SUBROUTINE FFT2B_64(M, N, A, LDA, WORK, LWORK) COMPLEX(8), DIMENSION(:,:) :: A INTEGER(8) :: M, N, LDA, LWORK REAL(8), DIMENSION(:) :: WORK C INTERFACE #include <sunperf.h> void zfft2b(int m, int n, doublecomplex *a, int lda, double *work, int lwork); void zfft2b_64(long m, long n, doublecomplex *a, long lda, double *work, long lwork);
Oracle Solaris Studio Performance Library zfft2b(3P) NAME zfft2b - compute a periodic sequence from its Fourier coefficients. The FFT operations are unnormalized, so a call of ZFFT2F followed by a call of ZFFT2B will multiply the input sequence by M*N. SYNOPSIS SUBROUTINE ZFFT2B(M, N, A, LDA, WORK, LWORK) DOUBLE COMPLEX A(LDA,*) INTEGER M, N, LDA, LWORK DOUBLE PRECISION WORK(*) SUBROUTINE ZFFT2B_64(M, N, A, LDA, WORK, LWORK) DOUBLE COMPLEX A(LDA,*) INTEGER*8 M, N, LDA, LWORK DOUBLE PRECISION WORK(*) F95 INTERFACE SUBROUTINE FFT2B(M, N, A, LDA, WORK, LWORK) COMPLEX(8), DIMENSION(:,:) :: A INTEGER :: M, N, LDA, LWORK REAL(8), DIMENSION(:) :: WORK SUBROUTINE FFT2B_64(M, N, A, LDA, WORK, LWORK) COMPLEX(8), DIMENSION(:,:) :: A INTEGER(8) :: M, N, LDA, LWORK REAL(8), DIMENSION(:) :: WORK C INTERFACE #include <sunperf.h> void zfft2b(int m, int n, doublecomplex *a, int lda, double *work, int lwork); void zfft2b_64(long m, long n, doublecomplex *a, long lda, double *work, long lwork); ARGUMENTS M (input) Number of rows to be transformed. These subroutines are most efficient when M is a product of small primes. M >= 0. N (input) Number of columns to be transformed. These subroutines are most efficient when N is a product of small primes. N >= 0. A (input/output) On entry, a two-dimensional array A(M,N) that contains the sequences to be transformed. LDA (input) Leading dimension of the array containing the data to be transformed. LDA >= M. WORK (input) On entry, an array with dimension of at least LWORK. WORK must have been initialized by ZFFT2I. LWORK (input) The dimension of the array WORK. LWORK >= (4 * (M + N) + 30) 7 Nov 2015 zfft2b(3P)