st: Re: Varname default in a program

[Dani Tilley <tilleydani@yahoo.com>]

Thanks Nick. 



----- Original Message ----

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
From: Dani Tilley <tilleydani@yahoo.com>
To: stata <statalist@hsphsun2.harvard.edu>
Sent: Fri, July 9, 2010 2:16:13 PM
Subject: Varname default in a program

Hi,

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).

Any help is appreciated.

DF Tilley


      
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