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# st: tabstatmat question

 From "Alvarez,Sergio" To Subject st: tabstatmat question Date Thu, 01 Sep 2011 15:30:37 -0400

```Dear Statalisters,

```
I'm trying to create a matrix of the grouped means of a variable (num_typ3). The observations in my dataset are grouped by location (zone) and time period (wave).
```
```
Ideally the matrix would have the zones as the rows and the waves as the columns (or vice-versa), something like this:
```
WAVE
ZONE      1          2       ...
1      mean(1,1)  mean(1,2)
2      mean(2,1)  mean(2,2)
...

```
I would use the matrix to generate a variable that takes the mean value depending on the zone and wave, using something like:
```
gen meancatch = TABLE[zone,wave]

```
I believe I need to go this route, rather than directly creating the variable, because I'm creating a set of 'fake' alternatives for each 'real' observation, corresponding to each location. Each observation corresponds to a fishing trip, so the alternatives are the possible fishing trips that didn't happen. I'll do that using -reshape-.
```
Anyway, I thought -tabstatmat- would do the job, so I tried:

by zone wave, sort: tabstat num_typ3, stat(mean) save

```
Which gives me the elements of the ideal matrix one by one. Then I try:
```
tabstatmat TABLE

But this returns a 1x1 matrix:

symmetric table[1,1]
num_typ3
mean  .94892632

```
So my question is, where did I mess up? Or did I just misunderstand what -tabstatmat- does? Is there a convenient way to do this?
```

Sergio

--
Sergio Alvarez
Food and Resource Economics
University of Florida

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```