# Store the descriptive statistics of a variable in a macro in Stata

In Stata, the `.tabstat`

command computes aggregate statistics of variables such as mean and standard deviation, and its `save`

option stores these statistics in a matrix. For example, to get the N, mean, and standard deviation of personal income, enter:

. tabstat income, stat(n mean sd) save

The `stat()`

option specifies the aggregate statistics to be computed. `N`

(the number of valid observations), mean, and standard deviation are stored in a matrix
`r(StatTotal)`

. You may check for the presence of the matrix using the `return list`

command. You can also list the values of the matrix by running ```
matrix list
r(StatTotal)
```

as follows:

. return list matrices: r(StatTotal) : 3 x 1 . matrix list r(StatTotal)

To convert the special matrix into a typical matrix using the
`.matrix`

command, enter:

. matrix stats=r(StatTotal)

Finally, to convert a scalar, for example, the mean of the variable, into a macro, enter:

. local avg=stats[2,1]

If you want to save the matrix as a variable, enter the `.svmat`

command instead:

. clear . svmat stats, name(var)

You may clear memory before converting the matrix. Since the matrix has only one column (3x1), you may have one variable `var1`

with three observations for `N`

, mean, and standard deviation.

If you have questions about using statistical and mathematical software at Indiana University, contact Research Analytics.

*This is document* atuo *in the Knowledge Base.*

*Last modified on* 2019-02-11 16:53:45*.*