st: re: finding number of unique values of a variable

[Kit Baum <baum@bc.edu>]

< >
Dick said

I would like to loop over the list of variables in a data set and
find the number of unique values for each variable, regardless
of whether the variable is numeric or string. There are several
ways to do this for a numeric variable, but I don't see a convenient
way to do it for a mixture of string and numeric variables.


I am frequently reminded by Nick Cox that when I say unique I mean  
distinct. If you -findit distinct- you will locate some of his pearls  
of wisdom:

 http://www.stata.com/support/faqs/data/distinct.html
http://www.stata.com/support/faqs/data/distinctstrings.html

which may be helpful. Also referenced are some of his Speaking Stata  
columns in the Stata Journal, which are freely downloadable through  
mid-2005.

Kit Baum, Boston College Economics and DIW Berlin
http://ideas.repec.org/e/pba1.html
An Introduction to Modern Econometrics Using Stata:
http://www.stata-press.com/books/imeus.html


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