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09.14.2008 at 11:24AM PDT, ID: 23730336
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9.2

How do I modify this matlab program to read in a wave file to do some calculations

Asked by yankeebushsoftware in Signal Processing, Programming Languages, MatLab Programming Language

I have this program to detect wheezing in some wave files, but I need to read in the wave file, can someone show me how to do that, I don't know matlab that well.Start Free Trial 
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Source code for wheeze detection:
function wheeze_ratio = wheezefind(y,Fs)
%Spectrogram parameters:
NFFT = 2048;
WINDOW = 128;
numoverlap = 108;
DISPLAY_IMAGES = 0;
%window of interest (Hz, Seconds)
MINFREQ = 200;
MAXFREQ = 2200;
MINTIME = 0;
MAXTIME = 10;
%define length of wheezes
widthMIN=25;
widthMAX=10000;
[B,Freqs,Times] = specgram(y,NFFT,Fs,WINDOW,numoverlap);
MINFREQ = sum(Freqs <= MINFREQ);
MAXFREQ = sum(Freqs <= MAXFREQ);
MINTIME = sum(Times <= MINTIME);
MAXTIME = sum(Times <= MAXTIME);
B = abs(B);
if DISPLAY_IMAGES
figure
imagesc(Times(MINTIME:MAXTIME),Freqs,20*log10(B(:,MINTIME:MAXTIME))),axis xy, colormap('jet')
end
%image is B(freq,time)
specdata = B';
peaksmap = specdata;
% %%%%%%%%%VECTOR METHOD%%%%%%%%%%%
the_mean = repmat(mean(specdata(MINTIME:MAXTIME,:),2),1,length(Freqs));
column = specdata(MINTIME:MAXTIME,:) - the_mean;
variance = repmat(sqrt(1./(length(Freqs)*sum((column.^2),2))),1,length(Freqs));
column = column ./ variance;
peaks = (column > (.5*variance)) .* ((column - circshift(column,[0 1])) > 0) .* ((column - ...
circshift(column,[0 -1])) > 0);
peakdisp = peaks | circshift(peaks,[0 1]) | circshift(peaks,[1 1]) | circshift(peaks,[1 0]);
if DISPLAY_IMAGES
figure
imagesc(Times(MINTIME:MAXTIME),Freqs(MINFREQ:MAXFREQ),...
(peakdisp(MINTIME:MAXTIME,MINFREQ:MAXFREQ)')),axis xy, colormap('jet')
end
peakscore = peaks .* ((column - (circshift(column,[0 1]) + circshift(column,[0 2]) + ...
circshift(column,[0 3])) / 3) > (2.5*variance));
peakscore = peakscore + peaks .* ((column - ((circshift(column,[0 -1]) + ...
circshift(column,[0 -2]) + circshift(column,[0 -3])) / 3)) > (2.5*variance));
peakscore = peakscore + peaks .* (((column - circshift(column,[0 1])) > (2*variance)) .* ...
((column - circshift(column,[0 -1])) > (2*variance)));
peakscore = peakscore + peaks .* (((column - circshift(column,[0 2])) > (3.5*variance)) .* ...
((column - circshift(column,[0 -2])) > (3.5*variance)));
peakscore = peakscore - peaks .* (1 - (column - ((...
circshift(peaks,[0 1]) + circshift(peaks,[0 2]) + circshift(peaks,[0 3]) + ...
circshift(peaks,[0 -1]) + circshift(peaks,[0 -2]) + circshift(peaks,[0 -3])) / 6) > 0));
peakscore = peakscore + peaks .* ((column - ((...
circshift(column,[0 1]) + circshift(column,[0 2]) + circshift(column,[0 3]) + ...
circshift(column,[0 -1]) + circshift(column,[0 -2]) + circshift(column,[0 -3])) / 6)) ...
> (3*variance));
peaksmap = peakscore;
%%%%%%%%%%%%%%%%%
120
if DISPLAY_IMAGES
figure
imagesc(Times(MINTIME:MAXTIME),Freqs(MINFREQ:MAXFREQ), ...
(peaksmap(MINTIME:MAXTIME,MINFREQ:MAXFREQ)')),axis xy, colormap('jet')
end
line = sum(peaksmap(MINTIME:MAXTIME,MINFREQ:MAXFREQ),2);
if DISPLAY_IMAGES
figure
imagesc(Times(MINTIME:MAXTIME),Freqs(MINFREQ:MAXFREQ),line'),axis xy, colormap('jet')
end
newline = zeros(size(line));
ones=0; % ones counter
prom=0;
for i=1:length(line)
% increment the counter of pre-wheezes
if line(i)
prom = prom + line(i);
ones = ones + 1;
end
% a wheeze is defined as a set (width*prominence) product of 1s followed by a 0
if (line(i) == 0)
if (prom >= widthMIN) & (prom <= widthMAX)
%mark with a band
for n = 0:ones
if i-n > 0
newline(i-n) = 1;
end
end
end
ones=0;
prom=0;
end
end
if DISPLAY_IMAGES
figure
imagesc(Times(MINTIME:MAXTIME),Freqs,newline'),axis xy,colormap('jet')
end
wheeze_ratio = mean(newline);
end
[+][-]09.19.2008 at 12:31AM PDT, ID: 22518674

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[+][-]09.20.2008 at 06:56PM PDT, ID: 22532871

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About this solution

Zones: Signal Processing, Programming Languages, MatLab Programming Language
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Solution Provided By: LukeyJay
Participating Experts: 1
Solution Grade: A
 
 
 
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