st: Filling upper triangle of a symetric matrix

 From "Ronnie Babigumira" To "Statalist" Subject st: Filling upper triangle of a symetric matrix Date Wed, 26 Mar 2003 16:43:00 +0100

```Dear listers
(Stata 8, win 2K) I have a correlation matrix in excel (I dont have the data
from which it was obtained) and I would like to perform factor analysis on
this matrix. This is possible if by using corr2data, I generate the
underlying data and then I can perform the factor analysis.

Here is my correlation matrix
Corr Matrix
1
0.439	1
0.41	0.351	1
0.288	0.354	0.164	1
0.329	0.32	0.19	0.595	1
0.248	0.329	0.181	0.47	0.464	1

If I try to read this in stata (using insheet), I get 6 new variables with
missing cases

+---------------------------------------+
|   v1     v2     v3     v4     v5   v6 |
|---------------------------------------|
|    1      .      .      .      .    . |
| .439      1      .      .      .    . |
|  .41   .351      1      .      .    . |
| .288   .354   .164      1      .    . |
| .329    .32    .19   .595      1    . |
|---------------------------------------|
| .248   .329   .181    .47   .464    1 |
+---------------------------------------+
I then convert this into a matrix using mkmat and I get

a[6,6]
1          .          .          .          .          .
.43900001          1          .          .          .          .
.41  .35100001          1          .          .          .
.28799999       .354       .164          1          .          .
.329  .31999999        .19  .59500003          1          .
.248       .329  .18099999        .47  .46399999          1

Question. How can I tell stata that this is a symetric matrix and fill in
the missing ijs with the corresponding ji values? (or, how can I do this in
excel)

Ronnie

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```