www.pudn.com > 医学算法.rar > fft

.TH FFT 3 "Ultrasonics Lab"
.SH NAME
fft - One Dimensional Fast Fourier Transform
.SH SYNOPSIS
fft(ar,ai,m,opt)
.br
float *ar, *ai;
.br
int m, opt;
.SH DESCRIPTION
This routine calculates a one dimensional fft
of a signal in place.
The first two arguments,
.B ar
and
.B ai
are
pointers to single precision arrays of numbers.
The first one
should be the real values, while the
second argument should point to the
imaginary values.
.PP
The third argument,
.B m,
is the log (base 2) of the size of each array.
Thus 10 would correspond to taking
the FFT of a 1024 element complex sequence.
.PP
The last argument,
.B opt,
represents the direction.
If the direction is zero then the forward
transform is taken,
otherwise the inverse transform is calculated.
.SH DIAGNOSTICS
None