How do I plot a 144000 sample sound file with 400 samples in different windows with for loop?

I have a plot of an audio file with 144000 samples. I want to draw these 144000 sample sound files in 400 separate windows each. Each window will contain 400 instances of it, and I want to interpret it in every 400 windows. Can you help me?

[Jan]

What does this mean: "Each window will contain 400 instances of it" - what is "it"?

[furkan akhan]

I mean the plot in the screenshot I took is 144000 samples. I want to plot this as 400 samples in separate windows.

sound=structWheeze(2,1).SoundData;
for i=1:200:144000
    first=sound(i:i+399);

end
plot(first)

I tried this code but it didn't work

Answer 1

[Star Strider]

If ‘y’ is the signal, and you have the Signal Processing Toolbox, use the buffer function:

framelen = 400;
frames = buffer(y, framelen);

The ‘frames’ variable is a (400x360) matrix, and each column is a non-overlapping segment of ‘y’ that is 400 samples in length. It would also be possible to use the reshape function, however buffer is the easier option.

To plot them, simply plot each column.

EDIT —

The loop posted in the Comment would indicate that the plots would have 50% overlap, since the segment indices would be:

           1         400
         201         600
         401         800
         601        1000
         801        1200

and so to the end of the file. The buffer function can also do that.

[furkan akhan]

How can i apply this command to my own code?

[Star Strider]

To use buffer without overlapping the segments:

framelen = 400;
frames = buffer(sound,framelen);

or with a 200-sample overlap:

framelen = 400;
overlap = 200;
frames = buffer(sound, framelen, overlap);

Experiment to get the result you want.

[furkan akhan]

Thanks a lot but i wanna ask you a question again. How can I plot these 400x360 data in separate windows? To examine each sample of 400.

[Star Strider]

There are at least two options:

for k = 1:size(frames,2)
    figure
    plot(frames(:,k))                                   % Plot Each In Separate Figure
end

or:

for k1 = 1:fix(size(frames,2)/10)
    figure
    for k2 = 1:10                                       % 36 Figures With 10 subplot Axes Each
        subplot(5,2,k2)
        plot(frames(:,k2+10*(k1-1)))
        title(sprintf('Column %3d', k2+10*(k1-1)))
    end
end

and any number of variations on the subplot version. Experiment to get the result you want.