RCFFT2(3F)RCFFT2(3F)NAMERCFFT2 - Calculate a real-to-complex Fourier synthesis/analysis.
DESCRIPTION
A subroutine that calculates a Fourier synthesis if the sign of IX is
negative and a Fourier analysis if the sign of IX is positive.
Call from FORTRAN:
CALL RCFFT2(init,ix,n,x,work,y)
init <>0 Generates sine and cosine tables in WORK
= 0 Calculates Fourier transforms using sine and
cosine tables of previous call.
ix > 0 Calculates Fourier analysis
<=0 Calculates Fourier synthesis.
n Size of Fourier transform; 2**m where 2<=m.
x Input vector. Vector of n real values.
work Working storage. Vector of (3/2)n+2 complex values.
y Result vector. Vector of (n/2)+1 complex values.
For equations and other additional information, see the CRAY-1 Computer
Systems - Library Reference Manual, SR-0014, page 4-52.
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