mirror of
https://github.com/mborgerding/kissfft.git
synced 2025-05-27 21:20:27 -04:00
94 lines
2.4 KiB
Python
Executable File
94 lines
2.4 KiB
Python
Executable File
#!/usr/local/bin/python2.3
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import FFT
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import sys
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import random
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import re
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j=complex(0,1)
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def randvec(n,iscomplex):
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if iscomplex:
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return [
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int(random.uniform(-32768,32767) ) + j*int(random.uniform(-32768,32767) )
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for i in range(n) ]
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else:
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return [ int(random.uniform(-32768,32767) ) for i in range(n) ]
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def c_format(v,round=0):
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if round:
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return ','.join( [ '{%d,%d}' %(int(c.real),int(c.imag) ) for c in v ] )
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else:
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s= ','.join( [ '{%.60f ,%.60f }' %(c.real,c.imag) for c in v ] )
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return re.sub(r'\.?0+ ',' ',s)
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def test_vec( v,inverse ):
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if inverse:
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tvecout = FFT.inverse_fft(v)
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tvecout = [ c * len(v) for c in tvecout ]
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else:
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tvecout = FFT.fft(v)
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s="""#define NFFT %d""" % len(v) + """
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{
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double snr;
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kiss_fft_cpx test_vec_in[NFFT] = { """ + c_format(v) + """};
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kiss_fft_cpx test_vec_out[NFFT] = {""" + c_format( tvecout ) + """};
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kiss_fft_cpx testbuf[NFFT];
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void * cfg = kiss_fft_alloc(NFFT,%d);""" % inverse + """
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kiss_fft(cfg,test_vec_in,testbuf);
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snr = snr_compare(test_vec_out,testbuf,NFFT);
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printf("FFT n=%d, inverse=%d, snr = %g dB\\n",NFFT,""" + str(inverse) + """,snr);
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free(cfg);
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}
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#undef NFFT
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"""
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return s
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def compare_func():
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s="""
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double snr_compare( kiss_fft_cpx * test_vec_out,kiss_fft_cpx * testbuf, int n)
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{
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int k;
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double sigpow,noisepow,err,snr,scale=0;
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sigpow = noisepow = .000000000000000000000000000001;
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for (k=0;k<n;++k) {
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sigpow += test_vec_out[k].r * test_vec_out[k].i +
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test_vec_out[k].i * test_vec_out[k].i;
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err = test_vec_out[k].r - testbuf[k].r;
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noisepow += err * err;
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err = test_vec_out[k].i - testbuf[k].i;
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noisepow += err * err;
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if (test_vec_out[k].r)
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scale += testbuf[k].r / test_vec_out[k].r;
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}
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snr = 10*log10( sigpow / noisepow );
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scale /= n;
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if (snr<10)
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printf( "\\npoor snr, try a scaling factor %f\\n" , scale );
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return snr;
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}
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"""
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return s
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def main():
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fftsizes = sys.argv[1:]
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if not fftsizes:
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fftsizes = [ 1800 ]
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print '#include "kiss_fft.h"'
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print compare_func()
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print "int main() {"
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for n in fftsizes:
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v = randvec(int(n),1)
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print test_vec(v,0)
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print test_vec(v,1)
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print """
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return 0;
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}
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"""
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if __name__ == "__main__":
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main()
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