How can I compute the mean of an EMG signal that I loaded it in MATLAB?

I loaded my signal and now I want to compute the mean and absolut of it, is there any code to do these?

Answer 1

[Image Analyst]

The mean() and abs() functions immediately spring to mind.

[Image Analyst]

Of course it's possible to have a negative mean. And mean() can work with any size or shape of matrix.

If you have a vertical vector and want the mean of the absolute values of it, you can do

theMean = mean(abs(yourVerticalVector));

[Ghazal Hnr]

when I use mean the obtained answer is negative, isn't it a problem?

[Image Analyst]

Having a negative mean is not a problem. What is the mean of [-3, -4, -8]? It's negative of course, as it should be. Using my code you will not get a negative because it takes the absolute value of the vector. Maybe you want that - who knows? What do you really want?

[Ghazal Hnr]

I just want the mean of signal but I thought I can't use mean for a signal, it is a practice for one of my lessons. Thank you for your help

[Image Analyst]

Why did you think that? Did the practice question specifically say not to use the built-in mean() or sum() functions? If so, you can use a for loop:

theSum = 0;
for k = 1 : length(yourVector)
    theSum = theSum + yourVector(k);
end
theMean = theSum / length(yourVector);

Or

theSum = theSum + abs(yourVector(k));

if you want the mean of the absolute value of the signal.

Answer 2

[ThB]

Just use

meanEMG = mean(EMG);

to compute a simple mean of an array. Or use

meanEMG = mean(mean(EMG));

if its a matrix

[Ghazal Hnr]

it is a vertical vector, is it ok to use these codes for it? when I use mean the obtained answer is negative, isn't it a problem?