How can I make and save a log file of calculated mean squared value from raw EMG when pushing button?

Hello, I and my teammates already wrote the code which calculates and shows mean squared value using recent 10 data points of EMG in real time. When the button is pushed, EMG data from 8 channels starts to be streamed and gathered and MSV also starts to be calculated and shown in real time.

I'd like to make and save a log for these calculated MSV values from the 8 channels which change over time. I've wrote some codes which allocates the new variable for saving MSV values. I've also tried the code by writing writematrix function to save the data as Excel file, but I failed to save. Are there any tips or advices for it?

This is the part of the code I've wrote.

msvlog = [0,0,0,0,0,0,0,0]; %Making New variable for saving calculated MSV from 8 channels

% Create a push button
btn = uibutton(fig,'state',...
    'Text','Streaming', ...
    'Position',[10, 700, 100, 30],...
    'ValueChangedFcn', @(btn,event) plotButtonPushed(btn, ax, myo, charac_val, msvlog, parameter));

Unrecognized function or variable 'fig'.

% 'ax' is for showing each channel of EMG

function plotButtonPushed(btn, ax, myo, charac_val, msvlog, parameter)
if btn.Value == true 
    myo.startStreaming; % Start Streaming_start record the emg
    for k = 1:6000
        emg = myo.emg_log; %myo.emg_log = function that starts to make log file of emg
        if numel(emg) ~= 0 && btn.Value == true
            x = 1:length(emg);
            for j = 1:8 %~106 line
                msv = 0;
                y = emg(:,j);
                ax(j).XLim = [0 length(emg)/200];
                ax(j).YLim = [-1 1];

                if length(y) > 10
                    for l = 0:9
                        msv = msv + y(length(y)-l)^2; %calculate msv using recent 10 dataset
                    end
                    msv = msv / 10;
                   
                else
                    for l = 0:length(y)-1
                        msv = msv + y(length(y)-l)^2;
                    end
                    msv = msv / length(y);
                    
                end
                charac_val(j).Text = num2str(msv);
                plot(ax(j),x/200,y)
                msvlog(k,j) = msv;
            end
        elseif btn.Value == false
            break;
        end
        drawnow; %Draw the real-time plot for raw EMG
        pause(0.02)
    end
else
    if myo.isStreaming == true
        myo.stopStreaming;
        writematrix(msvlog, parameter)
    end  %If streaming is on, making it off
end
end

Answer 1

[Tushar]

Hi Jiwon,

I understand that you are looking to save 'log files' from your MATLAB code. To achieve this, you can utilize the 'diary' command, which allows you to log everything on the command window to a file. Here is how you can use it:

• Ensure logging is turned on by using the following commands:

diary on; %turn logging on
get(0,'Diary'); %returns whether logging is 'on' or 'off'

• After every update of the calculated MSV values, display them as an output to the command window.
• To log the outputs to a file of your choice, use the following command:

diary myLogFile; %enable logging and save to myLogFile

For more information about 'log files' and how to use the 'diary' command, you can refer to the below documentation:

https://www.mathworks.com/help/matlab/ref/writematrix.html

Furthermore, please ensure that the 'parameter' in the line below corresponds to a valid filename with the correct extension. For Excel spreadsheet files, make sure to use file extensions such as .xls, .xlsm, or .xlsx

writematrix(msvlog, parameter);

For more information on the 'writematrix' function and writing to Excel files, you can refer to the below documentation:

https://www.mathworks.com/help/matlab/ref/writematrix.html

I hope this helps,

Tushar Agarwal