# st: RE: matrix-addressing rownames-inserting missings

 From "Scott Merryman" <[email protected]> To <[email protected]> Subject st: RE: matrix-addressing rownames-inserting missings Date Fri, 3 Jun 2005 05:41:31 -0500

```One way would be to use -capture- and nullmat.

For example:

matrix drop _all
matrix m = (1, 2, 3\ 4, 5, 6\ 7, 8, 9)

capture matrix b  = m["r2",1]
if _rc !=0 {
matrix b = (nullmat(b),.)
}

capture matrix d=m["d",1]
if _rc !=0 {
matrix d = (nullmat(d),.)
}

matrix list m
matrix list b
matrix list d

Hope this helps,
Scott

> -----Original Message-----
> From: [email protected] [mailto:owner-
> [email protected]] On Behalf Of Nicole Schneeweis
> Sent: Friday, June 03, 2005 4:25 AM
> To: [email protected]
> Subject: st: matrix-addressing rownames-inserting missings
>
> hello,
>
> i'm exporting cells out of matrices, and have a problem when cells are
> missing.
>
> To be more precise:
>
> it's important for me, to address the relevant row of a matrix with its
> name, not with its number (because it's a loop and numbers are changing,
> not names)
>
> e.g. matrix M  is defined with rownames, a, b, c. I need the first
> column of row "b" and therefore I create a new matrix: matrix
> B=M["b",1].
>
> Now, the problem is the following: in some matrices (of the loop) not
> all rows are available, but eg only the rows a and c.
>
> The loop stops when "b" is not found! I want Stata to insert a missing
> and going on, rather than giving the error message and stopping the
> loop!
>
> Possilbly there is an option, how to treat not-found-rows or an
> if-function has to be implemented. But how?
>
> Does anyone know a solution to this problem???
>
> Thanks
> Nicole
>
>
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```