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https://github.com/mborgerding/kissfft.git
synced 2025-05-27 21:20:27 -04:00
59 lines
1.4 KiB
Matlab
Executable File
59 lines
1.4 KiB
Matlab
Executable File
function snr= testkiss( nfft , nrows, prec )
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printf('### testing SNR for %d x %d point %s FFTs\n' , nfft,nrows,prec);
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if strcmp( prec ,'short')
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scale_t2f=nfft*nrows;
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scale_f2t=nfft*nrows;
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else
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scale_t2f=1;
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scale_f2t=1/(nfft*nrows);
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endif
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kfft= sprintf('./fftutil_%s',prec);
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sig=floor(32767*rand(nrows,nfft)) + j*floor(32767*rand(nrows,nfft));
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filesave('time.dat',prec,sig);
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if nrows > 1
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cmd = sprintf('%s -r %d -n %d time.dat freq.dat',kfft,nrows,nfft);
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else
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cmd = sprintf('%s -n %d time.dat freq.dat',kfft,nfft);
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endif
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system(cmd);
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Fsigcomp=fileload('freq.dat',prec,1,nrows ) * scale_t2f;
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if nrows == 1,
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Fsig=fft(sig);
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else
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Fsig=fft2(sig);
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endif
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diff = Fsig - Fsigcomp;
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noise_pow = sum( conj(diff).*diff );
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sig_pow = sum( conj(Fsig).*Fsig );
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snr_t2f = 10*log10( sig_pow / noise_pow )
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avg_scale = mean( abs(Fsig) ./ abs(Fsigcomp) );
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var_scale = var( abs(Fsig) ./ abs(Fsigcomp) );
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if nrows > 1
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cmd = sprintf('%s -r %d -i -n %d freq.dat time2.dat',kfft,nrows,nfft);
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else
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cmd = sprintf('%s -i -n %d freq.dat time2.dat',kfft,nfft);
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endif
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system(cmd);
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sigcomp=fileload('time2.dat',prec,1,nrows) * scale_f2t;
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diff = sig - sigcomp;
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noise_pow = sum( conj(diff).*diff );
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sig_pow = sum( conj(sig).*sig );
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snr_f2t = 10*log10( sig_pow / noise_pow )
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avg_scale = mean( abs(sig) ./ abs(sigcomp) );
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var_scale = var( abs(sig) ./ abs(sigcomp) );
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snr=[snr_t2f snr_f2t];
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endfunction
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