#!/usr/bin/env python2.3# use FFTPACK as a baselineimport FFTfrom Numeric import *import mathimport randomimport sysimport structimport fftpi=math.pie=math.ej=complex(0,1)lims=(-32768,32767)def randbuf(n,cpx=1):    res = array( [ random.uniform( lims[0],lims[1] ) for i in range(n) ] )    if cpx:        res = res + j*randbuf(n,0)    return resdef main():    from getopt import getopt    import popen2    opts,args = getopt( sys.argv[1:],'u:n:Rt:' )    opts=dict(opts)    exitcode=0    util = opts.get('-u','./kf_float')    try:        dims = [ int(d) for d in opts['-n'].split(',')]        cpx = opts.get('-R') is None        fmt=opts.get('-t','f')    except KeyError:        sys.stderr.write("""        usage: compfft.py         -n d1[,d2,d3...]  : FFT dimension(s)        -u utilname : see sample_code/fftutil.c, default = ./kf_float        -R : real-optimized version\n""")        sys.exit(1)    x = fft.make_random( dims )    cmd = '%s -n %s ' % ( util, ','.join([ str(d) for d in dims]) )    if cpx:        xout = FFT.fftnd(x)        xout = reshape(xout,(size(xout),))    else:        cmd += '-R '        xout = FFT.real_fft(x)    proc = popen2.Popen3( cmd , bufsize=len(x) )    proc.tochild.write( dopack( x , fmt ,cpx ) )    proc.tochild.close()    xoutcomp = dounpack( proc.fromchild.read( ) , fmt ,1 )    #xoutcomp = reshape( xoutcomp , dims )    sig = xout * conjugate(xout)    sigpow = sum( sig )    diff = xout-xoutcomp    noisepow = sum( diff * conjugate(diff) )    snr = 10 * math.log10(abs( sigpow / noisepow ) )    if snr<100:        print xout        print xoutcomp        exitcode=1    print 'NFFT=%s,SNR = %f dB' % (str(dims),snr)    sys.exit(exitcode)def dopack(x,fmt,cpx):    x = reshape( x, ( size(x),) )    if cpx:        s = ''.join( [ struct.pack('ff',c.real,c.imag) for c in x ] )    else:        s = ''.join( [ struct.pack('f',c) for c in x ] )    return s def dounpack(x,fmt,cpx):    uf = fmt * ( len(x) / 4 )    s = struct.unpack(uf,x)    if cpx:        return array(s[::2]) + array( s[1::2] )*j    else:            return array(s )if __name__ == "__main__":    main()