Error in helperspeechSpectrograms (line 14) numHops = ceil((segmentDuration - frameDurat​ion)/hopDu​ration);

function X = helperspeechSpectrograms(ads,segmentDuration,frameDuration,hopDuration,numBands)

% This function is only for use in the

% "Spoken Digit Recognition with Wavelet Scattering and Deep Learning"

% example. It may change or be removed in a future release.

%

% helperspeechSpectrograms(ads,segmentDuration,frameDuration,hopDuration,numBands)

% computes speech spectrograms for the files in the datastore ads.

% segmentDuration is the total duration of the speech clips (in seconds),

% frameDuration the duration of each spectrogram frame, hopDuration the

% time shift between each spectrogram frame, and numBands the number of

% frequency bands.

disp("Computing speech spectrograms...");

numHops = ceil((segmentDuration - frameDuration)/hopDuration);

numFiles = length(ads.Files);

X = zeros([numBands,numHops,1,numFiles],'single');

for i = 1:numFiles

[x,info] = read(ads);

x = normalizeAndResize(x);

fs = info.SampleRate;

frameLength = round(frameDuration*fs);

hopLength = round(hopDuration*fs);

spec = melSpectrogram(x,fs, ...

'Window',hamming(frameLength,'periodic'), ...

'OverlapLength',frameLength - hopLength, ...

'FFTLength',2048, ...

'NumBands',numBands, ...

'FrequencyRange',[50,4000]);

% If the spectrogram is less wide than numHops, then put spectrogram in

% the middle of X.

w = size(spec,2);

left = floor((numHops-w)/2)+1;

ind = left:left+w-1;

X(:,ind,1,i) = spec;

if mod(i,500) == 0

disp("Processed " + i + " files out of " + numFiles)

end

end

disp("...done");

end

Error in helperspeechSpectrograms (line 14) numHops = ceil((segmentDuration - frameDuration)/hopDuration);