A view is what is says: a view.
When you -insheet- data the second time, F is updated, and you get F
== A. Is this the "problem" you are refering to? Maybe in this case
you need -st_data()- instead of -st_view()?
An example is attached below.
/Jesper
Example:
-------------------begin-------------------
. mata
--- mata (type end to exit) ---
: mata clear
: stata("insheet using test.txt, clear")
(3 vars, 10 obs)
: st_view(F=.,.,.)
: F
1 2 3
+-------------------------+
1 | 4099 22 3 |
2 | 4749 17 3 |
3 | 3799 22 . |
4 | 4816 20 3 |
5 | 7827 15 4 |
6 | 5788 18 3 |
7 | 4453 26 . |
8 | 5189 20 3 |
9 | 10372 16 3 |
10 | 4082 19 3 |
+-------------------------+
: stata("insheet using test2.txt, clear")
(3 vars, 10 obs)
: st_view(A=.,.,.)
: A
1 2 3
+----------------------+
1 | 11 2930 186 |
2 | 11 3350 173 |
3 | 12 2640 168 |
4 | 16 3250 196 |
5 | 20 4080 222 |
6 | 21 3670 218 |
7 | 10 2230 170 |
8 | 16 3280 200 |
9 | 17 3880 207 |
10 | 13 3400 200 |
+----------------------+
: F
1 2 3
+----------------------+
1 | 11 2930 186 |
2 | 11 3350 173 |
3 | 12 2640 168 |
4 | 16 3250 196 |
5 | 20 4080 222 |
6 | 21 3670 218 |
7 | 10 2230 170 |
8 | 16 3280 200 |
9 | 17 3880 207 |
10 | 13 3400 200 |
+----------------------+
:
-------------------end---------------------
On Jan 22, 2008 11:38 PM, Raphael Fraser <[email protected]> wrote:
> Can anyone explain why the matrix X gives the incorrect result?
> When I run the code and check the contents of the matrix A and F.
> A is the matrix view of amt.csv but A is also the view of the same file.
> At some point the matrix F becomes A. What's the problem?
>
> ***begin here***
> mata clear
> stata("insheet using freq.csv, clear")
> stata("drop subjectid")
> st_view(F=., ., .) /* 91 subjects x 110 foods */
>
> stata("insheet using amt.csv, clear")
> stata("drop subjectid")
> st_view(A=., ., .) /* 91 subjects x 110 foods */
> X = 0.01*(A:*F)
> ***end here***
>
> Raphael
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