--- In�s Rodr�guez <[email protected]> wrote:
> > What mean when a variable appears in red?
--- Chiara Mussida <[email protected]> wrote:
> if it is red into the data editor it means that it is considered as
> "string" variable and stata does not allow any regression with
> variable expressed in this way
Strings are basically letters, and Stata can do very little math with
letters (how much is a + b?), which is why you cannot directly enter a
string variable into for instance -regress-, as Chiara noted. However,
a string variable often identifies different groups, i.e. represents a
categorical variable. If this is the case you can use it in regression
by using the -xi- prefix. Alternatively you can turn it into a numeric
variable (give each category a number, and attach a the string to it
using a value label) using -encode-.
Hope this helps,
Maarten
-----------------------------------------
Maarten L. Buis
Department of Social Research Methodology
Vrije Universiteit Amsterdam
Boelelaan 1081
1081 HV Amsterdam
The Netherlands
visiting address:
Buitenveldertselaan 3 (Metropolitan), room Z434
+31 20 5986715
http://home.fsw.vu.nl/m.buis/
-----------------------------------------
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