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standard deviation problem

standard deviation problem

standard deviation problem

(OP)
Hi All,

I found the code below, where M is a three dimensional array and M is a matrix (the third dimension of M)

CODE

  A = M(:,:,1);
  meanA = mean(mean(A));
  stdA = std(A(:));
and I don't know what it means std(A(:))
Is the same as std(A) ie standard deviation of A matrix?

Thanks in advance

RE: standard deviation problem

Have you bothered to read the help file entry for std?

TTFN



RE: standard deviation problem

from your link:

"If X is a matrix, std(X) returns a row vector containing the standard deviation of the elements of each column of X. If X is a multidimensional array, std(X) is the standard deviation of the elements along the first nonsingleton dimension of X."

So, obviously, std(A) is NOT the std of the matrix.

TTFN



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