44 lines
661 B
Mathematica
44 lines
661 B
Mathematica
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% av_imp.m
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% David Rowe Aug 2012
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% Averages the impulse response samples
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function imp = av_imp(imp_filename, period_in_secs, st, en)
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f = fopen(imp_filename,"rb");
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s = fread(f, Inf, "short")';
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Fs = 8000;
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n = period_in_secs * Fs;
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[r c] = size(s);
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imp = zeros(1,n);
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for i=1:n:c-n
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imp = imp + s(i:i+n-1);
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endfor
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% user supplies start and end samples after viweing plot
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if (nargin == 4)
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imp = imp(st:en);
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end
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% normalise
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imp /= sqrt(sum(imp .^ 2));
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[h w] = freqz(imp, 1, 4000);
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figure(1);
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clf;
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plot(imp);
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figure(2);
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clf;
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subplot(211)
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plot(10*log10(abs(h)))
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subplot(212)
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plot(angle(h))
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endfunction
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