MATLAB: 31 ●5 How to use Dynamic Time Warping (DTW) algorithm in matlab

dspdtw

I am new in matlab. I've been browsing for few hours and I'm still getting errors. I want to know how to use dtw algorithm in matlab and I want to know the output of these two audio files using dtw algorithm. this is my code:

fftNyol = fft(audioread('C:\Users\handy\Documents\MATLAB\my_recording_1.wav'));
fftFajar = fft(audioread('C:\Users\handy\Documents\MATLAB\fajar.wav'));
dist = dtw(fftNyol,fftFajar);

this is error message from matlab:

Error using zeros
Requested 137281x87361 (89.4GB) array exceeds maximum array size preference. Creation of arrays greater than this limit
may take a long time and cause MATLAB to become unresponsive. See array size limit or preference panel for more
information.
Error in dtw (line 27)
D=zeros(ns+1,nt+1)+Inf; % cache matrix
Error in test (line 15)
dist = dtw(fftNyol,fftFajar);

Best Answer

You are not using Mathworks dtw() from the signal processing toolbox. Mathworks dtw() has comments at line 27.

Related Solutions

MATLAB: Audio file (.wav) being overwritten

You have

speech = ('coch4.wav');
speech2 = speech;

So your speech2 filename is the same as your speech filename.

[y,Fs]=audioread(speech2); %don't use wavread or audioread

So you read from coch4.wav via speech2 filename

audiowrite(speech, speech_trimmed, 44100);

and then you write to the file name given by speech, which is the same as the filename given by speech2, so you are writing to the same file that you read the data from.

MATLAB: Clustering Time Series with DTW

I think the error is due the reason that dtw function operates on 2 signals only and the output is always a scalar.

As per the description of 'Distance' Name Value Pair Argument of the kmedoids function:

"See pdist for the definition of each distance metric. kmedoids supports all distance metrics supported by pdist."

And as per the description of Distance input argument of the pdist function for custom distance:

"@distfun

Custom distance function handle. A distance function has the form

function D2 = distfun(ZI,ZJ)
% calculation of distance
...

where

ZI is a 1-by-n vector containing a single observation.
ZJ is an m2-by-n matrix containing multiple observations. distfun must accept a matrix ZJ with an arbitrary number of observations.
D2 is an m2-by-1 vector of distances, and D2(k) is the distance between observations ZI and ZJ(k,:)."

Hence you can't use the dtw function handle directly and you can use it as follows:

data = rand(161,20);
[idx,c,sumd,d] = kmedoids(data,10,'Distance',@dtwf);
function dist = dtwf(x,y)
% n = numel(x);
m2 = size(y,1);
dist = zeros(m2,1);
for i=1:m2
    dist(i) = dtw(x,y(i,:));
end
end

Best Answer

Related Solutions

MATLAB: Audio file (.wav) being overwritten

MATLAB: Clustering Time Series with DTW

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