MATLAB: Standard deviation of a 1D array for a particular range

standard deviation

I would like to compute the standard deviation of my 1D array only for a particular range of indices.

my_array = [1 2 3 4 5 6 7 8 9 10];

i need to find Standard deviation for the elements of index 3 to 5 and 8 to 9.

i.e standard deviation of 3,4,5,8,9

std(my_array([3:5,8:9]))

numdev = floor((mean(S)-min(S))./std(S));

Determining the position of each standard deviation and plotting is left as a homework exercise.

Though possibly you want

numdev = floor((mean(S,2)-min(S,[],2))./std(S,[],2));

There are a lot of ways to do that. I would generate 3D array, where the third dimension will be of the size = # of rounds (5);

So you will have array X(m,n,r), where r=1:5 (if number of rounds is 5).

Now, use mean and stddiv with second argument 3:

MeanX=mean(X,3); StddivX=stddiv(X,3);

This will calculate mean and stddiv through 3rd dimension. As a result you obtain two 2D arrays, what you were asking.