```Date: Nov 7, 2013 3:38 PM
Author: Curious
Subject: Re: matrix from random selected data

"dony" wrote in message <l5fded\$qdf\$1@newscl01ah.mathworks.com>...> hai, > I have some problem> and i need help> i have matrix in 100x100, and from this matrix i have some random selected data.> from this data, i want to make it(selected data) to be a center of 3x3 new matrix> and then from this new matrix i want to calculate mean and standart deviation.> thanks for help % The last part should be simple% If A is your 3X3 "new" matrix, thenmean(A)% ormean(A(:))% or some variation of that should give your mean value.% Use std in the same way to get the standard deviationdoc meandoc std% Its not clear from your description how the "new"% matrix is derived from the original 100X100 matrix.% Can you provide an example?% I'm guessing that if ii & jj are a location within % your 100X100 matrix (call it X) then perhaps:A = X((ii-1):(ii+1),(jj-1):(jj+1))% might be what you want.% Note: the above requires 1<ii,jj<100% (can't be an edge).
```