How to get rid of error: Error using horzcat. Dimensions of array being concatenated are not consistent.

I have been working on speaker identification using MFCC and Pitch and after the process of feature extraction of files loaded from database and concatenating them into single array I recieve the error.

My code:

ads= audioDatastore(datadir,'FileExtensions','.wav','LabelSource','foldernames')

fs = dsInfo.SampleRate;
windowLength = round(0.03*fs);
overlapLength = round(0.025*fs);

features = [];
labels = [];

while hasdata(ads)
    [audioIn,dsInfo] = read(ads);
    
    melC = mfcc(audioIn,fs,'WindowLength',windowLength,'OverlapLength',overlapLength);
    f0 = pitch(audioIn,fs,'WindowLength',windowLength,'OverlapLength',overlapLength);
    feat =[melC,f0];                                    %Error on this line
    
    voicedSpeech = isVoicedSpeech(audioIn,fs,windowLength,overlapLength);
    
    feat(~voicedSpeech,:) = [];
    label = repelem(dsInfo.Label,size(feat,1));
    
    features = [features;feat];
    labels = [labels,label];
end

M = mean(features,1);
S = std(features,[],1);
features = (features-M)./S;


function voicedSpeech = isVoicedSpeech(x,fs,windowLength,overlapLength)

pwrThreshold = -40;
[segments,~] = buffer(x,windowLength,overlapLength,'nodelay');
pwr = pow2db(var(segments));
isSpeech = (pwr > pwrThreshold);

zcrThreshold = 1000;
zeroLoc = (x==0);
crossedZero = logical([0;diff(sign(x))]);
crossedZero(zeroLoc) = false;
[crossedZeroBuffered,~] = buffer(crossedZero,windowLength,overlapLength,'nodelay');
zcr = (sum(crossedZeroBuffered,1)*fs)/(2*windowLength);
isVoiced = (zcr < zcrThreshold);

voicedSpeech = isSpeech & isVoiced;

end

In workspace window

Value for f0 = 442x2 double

Value for melC= 442x14x2 double

[Geoff Hayes]

Smarth - the code is trying to concatenate a 442x2 array with a 442x14x2 array and so the error makes sense. How are you trying to combine the two? What should the dimensions of the concatenated result be?

Answer 1

[Srivardhan Gadila]

While concatenating arrays, the lengths of the dimensions must match except for the operating dimension.

Refer to horzcat, cat, Creating, Concatenating, and Expanding Matrices & Matrices and Arrays.