help mata mm_which()
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Title

    mm_which() -- Positions of nonzero elements


Syntax

        real vector mm_which(real vector v)


Description

    mm_which() returns the position of the nonzero elements in v.


Remarks

    Example:

        : x = uniform(10,1)
        
        : x
                          1
             +---------------+
           1 |  .6942035381  |
           2 |  .9866539028  |
           3 |   .339872522  |
           4 |  .4785448909  |
           5 |  .1890356159  |
           6 |  .2186723398  |
           7 |   .495693512  |
           8 |  .7756144393  |
           9 |   .733696372  |
          10 |  .4224797708  |
             +---------------+

        : mm_which(x:>.5)
               1
            +-----+
          1 |  1  |
          2 |  2  |
          3 |  8  |
          4 |  9  |
            +-----+


Conformability

    mm_which(v)
           v: 1 x c or r x 1
      result: 1 x c1 or r1 x 1.


Diagnostics

    mm_which(0) returns J(0,0,.).


Source code

    mm_which.mata


Author

    Ben Jann, ETH Zurich, jann@soz.gess.ethz.ch


Also see