standard deviation problem

[roco1]

Hi All,

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

  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

 

[IRstuff]

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

TTFN

 

[roco1]

I used

http://www.mathworks.com/access/helpdesk/help/techdoc/ref/std.html

and I dont found

std(MatrixName(:))

Thanks

 

[IRstuff]

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