st: RE: Varname default in a program

["Nick Cox" <n.j.cox@durham.ac.uk>]

I don't think there is a way to do this with -syntax- but that doesn't
matter. 

Within your program, after your -syntax- statement you go 

if "`pvar'" == "" local pvar "<default>" 

as if -pvar()- was not selected, the local macro pvar will be empty. Or,
rather, the local macro pvar will be undefined, but that's the same to
Stata. 

By the way, the -help- for -syntax- should be considered complete, so
guessing that there are undocumented extras is not a good strategy. 

Nick 
n.j.cox@durham.ac.uk 

Dani Tilley

I'm trying to write a program that will have the following syntax

syntax varlist(min=1 max=5), [Pvar(varname)]

However, I want the to have a default value for pvar so that when users
say 
-command var1 var2- the program returns no error and uses the default
variable 
for pvar. I know how this is done for numeric variables but can't do it
in this 
context. I tried [Pvar(varname default)] where default is a variable but
got 
r(197).


*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/