An undefined Array length for streamed LSL data

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BionicP 2020-11-9

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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/642430-an-undefined-array-length-for-streamed-lsl-data

评论： Walter Roberson 2020-11-9

Hi,

I am working on a project that streams EMG data from a device to MATLAB via LSL (Which is working streaming 4 channels perfectly). I am now at a cross roads where I need to define an array of a length i am unsure about as of now and save the data for processing.

My aim is to take the most recent 2000 pieces of information and work with those. Allow Matlab a couple seconds of processing and refresh the stream .

My question is how do i store the info in an array like this, i have tried at the bottom but it only stores the first 4 values.

The data comes as 4 channels.

Thanks!

% instantiate the library
disp('Loading the library...');
lib = lsl_loadlib();
% resolve a stream...
disp('Resolving an EEG stream...');
result = {};
while isempty(result)
    result = lsl_resolve_byprop(lib,'type','EEG'); end
% create a new inlet
disp('Opening an inlet...');
inlet = lsl_inlet(result{1});
disp('Now receiving chunked data...');
while true
    % get chunk from the inlet
    [chunk,stamps] = inlet.pull_chunk();
    for s=1:length(stamps)
        % and display it
        fprintf('%.2f\t',chunk(:,s));
        fprintf('%.5f\n',stamps(s));
    v = chunk(:,s);
    for i = 1:2000
        EMG = [v(i)];
        disp(EMG);
    end    
    end
    pause(0.05);
end