MATLAB: How to Segment EMG data into time intervals

datadata signal processingemgMATLAB

I have 2 minutes of filtered data that needs to be segmented into 20msec intervals, how would I go about doing that? It was collected at 2048 Hz and there is a total of 245762 data points.

Best Answer

One option is the Signal Processing Toolbox buffer function.

It uses samples as one of its arguments, however that is straightforward to calculate:

Fs = 2048;                                              % Sampling Frequency (samples/sec)
segment = 0.02;                                         % Segments (20 ms)
Samples = round(Fs * segment);                          % Sample Length

I use round here, however fix, floor or ceil would also work, depending on what you want.

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MATLAB: The resolution on the spectrogram plot is WAY too low

Experiment with more elements to your frequency vector, for example:

spectrogram(datVec,fs,[],[3:3:300],fs)

I’m not certain that will do what you want, however it’s always best to experiment.

MATLAB: Averaging lots of columns at once and then combining them

"...I cannot figure out a way to take the average of each col[o]umn without manually inputing it. "

Fs = 2048;                                             % Sampling Frequency 
segment = 0.25;                                        % Segments (250 msec)
Samples_fft = round (Fs * segment);                         % Sample Length
L_UTR_mean=mean(buffer(L_UTR_Detr, Samples_fft),2);     % time-domain average of columns
...

For averaging PSD, fft will operate by column; simply then use MATLAB array operations to operate over each column as if it were a vector then average the result as above.

See documentation for all functions--virtually all have the optional dim input paramter to tell them which dimension you wish to operate over if not the default by column.

Some, like std are tricky in that the dim input isn't the second so you may need to use a placeholder to get the desired argument.

Best Answer

Related Solutions

MATLAB: The resolution on the spectrogram plot is WAY too low

MATLAB: Averaging lots of columns at once and then combining them

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