sfftm1du,dfftm1du(3F) sfftm1du,dfftm1du(3F)NAME
dfftm1du, sfftm1du - Multiple 1D, Real to Complex Fast Fourier Transform.
FORTRAN SPECIFICATION
subroutine DFFTM1DU( job, n, p, sequence, inc, lda, workspace )
integer job, n, p, inc, lda
double precision sequence(lda,*), workspace(*)
subroutine SFFTM1DU( job, n, p, sequence, inc, lda, workspace )
integer job, n, p, inc, lda
real sequence(lda,*), workspace(*)
C SPECIFICATION
int dfftm1du( int job, int n, int p,
double *sequence, int inc, int lda,
double *workspace)
int sfftm1du( int job, int n, int p,
float *sequence, int inc, int lda,
float *workspace)
DESCRIPTION
DFFTM1DU and SFFTM1DU compute the complex Fourier transform of P real
periodic sequences of N samples each.
NOTE: These routines are provided only for compatibility with previous
releases of complib.
PARAMETERS
JOB - INTEGER
On entry specifies whether to perform a forward or backward Fast Fourier
Transform:
JOB = -1, forward FFT
JOB = 1, backward FFT Unchanged on exit.
N - INTEGER.
On entry, N specifies the number of elements in each sequence. Unchanged
on exit.
P - INTEGER.
On entry, P specifies the number of sequences. Unchanged on exit.
SEQUENCE - Array.
Array of DIMENSION ( LDA, p ). Array containing the (lda*p) elements for
the FFT. On exit, SEQUENCE is overwritten by its transform.
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sfftm1du,dfftm1du(3F) sfftm1du,dfftm1du(3F)
INC - INTEGER.
Increment between two consecutive elements of the sequence. Unchanged on
exit.
LDA - INTEGER.
On entry, LDA specifies the first dimension of the array SEQUENCE as
declared in the calling (sub)program. LDA must be at least max( 1,
2*((N1+2)/2) ). Unchanged on exit.
WORKSPACE - Array.
Array of dimension at least ( N + 15 ). Array containing the
Sines/Cosines and factorization of N. WORKSPACE needs to be initialized
by a call to sfftm1dui or dfftm1dui.
SEE ALSO
o32fft
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