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Computing the Standard Deviation of Each Column
Syntax colstd(x)
See Also colvar , colnorm , colmax , colmean , colmad , colmse

Description
Returns the standard deviation of each column of x where x is a real, double-precision, or complex matrix. The return value is a row vector with the same number of columns as x. If x is complex, the return value is double-precision, otherwise the return value has the same type as x. The jth element of the return value is
             --------------------------------------
            /        _   2                    _   2
           / | x   - x  |   + ... +  | x    - x  |
     \    /     1,j   j                  N,j   j
      \  /   ------------------------------------
       \/                     N - 1
where N is the number of rows in the matrix x and
                 N
     _       1  ----
     x   =  --- >     x
      j      N  ----   k,j
                k = 1

Example
If you enter
     x = [{0., 2., 4.}, {0., -1., 1.}]
     colstd(x)
O-Matrix will respond
     [ 2 , 1 ]