# st: Q about programming in mata re. syntax

 From "Xiaoheng Zhang" To statalist , "Ole Boysen" Subject st: Q about programming in mata re. syntax Date Thu, 25 Oct 2007 12:55:12 +0100

```hello all,I am just beginning programming in mata.I am using Stata
9.2.Suppose I have such a distance matrix of three firms.Distance of a
firm to itself should be 0 but I intentionally add a very large number
10000 to it.

: D
[symmetric]
1 2 3
+-------------------------+
1 | 10000 |
2 | 5 10000 |
3 | 7 2 10000 |
+-------------------------+
Then I run this programme and want to generate k=2 indicator matrice
but can only get error messenge.
two indicator matrice I need to get are

C1= 0 1 0
0 0 1
0 1 0

C2= 0 0 1
1 0 0
1 0 0

Where C1 indicating the nearest neighour of each firm by '1' and C2
indicating the second nearest neighour by'1'. You need to read along
each row.For example C1,first row means the nearest firm to firm 1 is
firm2, and so on.

. do "D:\Zhang documents\generate indicator matrix.do"

. mata
-------------------------- mata (type end to exit)
-------------------------------
: for (k=1; k<=2; k++) {
> r`k' = rowmin(D)
> C`k' = J(3 , 3 , 2)
> for (i=1; i<=3; i++) {
> for (j=1; j<=3; j++) {
> if (D[ i , j ] == r`k'[ i , 1 ])
> C`k'[ i , j ] = 1
> D[ i , j ] = D[ i , j ] + 10000
> else C`k'[ i , j ] = 0
'else' found where almost anything else expected
r(3000);

: }
expression invalid
r(3000);

: }
expression invalid
r(3000);

: }
expression invalid
r(3000);

: end
-----------------------------------------------------------

.
end of do-file

I really want to make it run but guess the part arond "else" should
have some syntax error. Or maybe r`k' is wrong in mata?

Return code 3000
(message varies)
There is an error in what you have typed. Mata cannot interpret
what you mean.

Could anyone help me?Thanks.

Kevin Zhang
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```