help mata mz_stdc()
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Title

    mz_stdc() -- Calculates the standard deviation of each column of a matrix


Syntax

    real matrix mz_stdc(x)


    where

            x:  real matrix


Description

    mz_stdc() computes the standard deviation of each column of a matrix and
    puts the result in a column vector.


Remarks

    Example:

        : x
               1   2   3   4
            +-----------------+
          1 |  1   3   5   6  |
          2 |  4   3   2   1  |
          3 |  7   5   3   2  |
          4 |  8   9   0   1  |
          5 |  4   6   8   9  |
          6 |  3   2   6   7  |
          7 |  1   4   5   7  |
          8 |  7   2   4   6  |
          9 |  1   4   0   3  |
          10|  1   4   6   7  |
            +-----------------+

        : mz_stdc(x)
                         1
            +---------------+
          1 |  2.790858092  |
          2 |  2.097617696  |
          3 |  2.643650675  |
          4 |  2.884826203  |
            +---------------+


Conformability

    mz_stdc(x)
         x:  r x c
    result:  c x 1.


Diagnostics

    mz_stdc() returns an empty column vector if x is a row vector. In
    addition, to compute the standard deviations, mz_stdc() uses N-1 rather
    than N as divisor, where N is the number of rows of matrix x. To convert
    to the alternate definition, multiply the output of mz_stdc() by
    sqrt((N-1)/N).


Source code

    mz_stdc.mata


Author

    Diallo Ibrahima Amadou, zavren@gmail.com


Also see

    Online:  help for [M-5] variance(), ltimbimata