Subscript indices must either be real positive integers or logicals.

I am trying to find the on/off times of EMG data, but MATLAB is giving the following error for the line with stars in my code:

Subscript indices must either be real positive integers or logicals.

I'm not sure what this means for my data. Any explanations would be helpful.

%%Find the on/off times of the EMG data within each rep

i = 1;
j = 1;
for r = 1:length(spans(:,1))
    if spans(r,1) == 1 && spans(r-1,1) == 0
        %The first marker point
        first_marker = r;
    end
end
thresh = 2.*std(EMG(1:first_marker));

for a = 1:7
    EMGreps = Repetitions{1,a};
    for c = 1:7
        for r = 1:length(EMGreps)
            if EMGreps(r,1) > thresh && EMGreps(r-1,1) < thresh
                % Determines if the EMG data is on
                On_EMG(i,c) = r/sampRate;
                i = i + 1;
            end
 ***           if EMGreps(r,1) < thresh && EMGreps(r-1,1) > thresh
                % Determines if the EMG data is off
                Off_EMG(j,c) = r/sampRate;
                j = j + 1;
            end
        end
    end
end

[Image Analyst]

Like almost everyone else, you don't include the full error message. Please copy and paste ALL THE RED TEXT - don't just snip out a small part of it that leaves out the crucial information like what line of code the error happened at.

[Alyna]

Actually, I did copy the entire error message. The only other line was commenting on the line in question, which I wrote about.

Answer 1

[Geoff Hayes]

Alyna - the error message is telling you that an index into an array must be a positive integer or logical. In your case, you are trying to use zero as an index into EMGreps at

 EMGreps(r-1,1)

which is the second condition in both of your if statements. Note how the index variable r starts at one, and so r-1 is zero. Start this variable at two and you should be good to continue

 for r=2:length(RMGreps)

     % etc

 end