excellent, thanks, Tim
On 1/29/08, Maarten buis <[email protected]> wrote:
> I would do it like this:
>
> local price "price"
>
> sysuse auto, clear
> unab vars: _all
> local ok : list price in vars
> if `ok' {
> do whatever you want to do with price
> }
>
> sysuse nlsw88, clear
> unab vars: _all
> local ok : list price in vars
> if `ok' {
> in this dataset price is absent
> so this block won't be executed
> }
>
> Hope this helps,
> Maarten
>
> --- Tim Wade <[email protected]> wrote:
>
> > Hi Statalisters:
> >
> > I have a series of datasets with many variables but some variables
> > are
> > missing from some data sets. I would like to evaluate the data sets
> > to
> > see if certain variables are present before executing some code. My
> > idea was to store all the names of the variables in a dataset in a
> > macro variable, then evaluate that macro variable using "strpos" to
> > see if the variable is present in the list, ending the code if strpos
> > returns 0. However, "strpos" does not seem to be able to evaluate my
> > macro variable. I have a feeling my problem may be the brute force
> > way
> > I am creating the macro (see below). When I manually create a local
> > variable, it works fine. Can anyone suggest a better approach?
> > Thanks
> > much in advance for any suggestions!
> >
> > For example:
> >
> > . sysuse auto.dta
> > (1978 Automobile Data)
> >
> > /*create local macro with list of variable names*/
> > . local x ""
> >
> > . foreach var of varlist _all {
> > 2. local x "`x'" " " "`var'"
> > 3. }
> >
> > . di "`x'"
> > make price mpg rep78 headroom trunk weight length turn displacement
> > gear_ratio foreign
> >
> > . di strpos("`x'", "price")
> > 0
> >
> > *"price" is not found by the "strpos" function
> >
> > /*create local variable manually*/
> >
> > . local y make price
> >
> > . di strpos("`y'", "price")
> > 6
> >
> > Tim
> > *
> > * For searches and help try:
> > * http://www.stata.com/support/faqs/res/findit.html
> > * http://www.stata.com/support/statalist/faq
> > * http://www.ats.ucla.edu/stat/stata/
> >
>
>
> -----------------------------------------
> 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/
> -----------------------------------------
>
>
> __________________________________________________________
> Sent from Yahoo! Mail - a smarter inbox http://uk.mail.yahoo.com
>
> *
> * For searches and help try:
> * http://www.stata.com/support/faqs/res/findit.html
> * http://www.stata.com/support/statalist/faq
> * http://www.ats.ucla.edu/stat/stata/
>
*
* For searches and help try:
* http://www.stata.com/support/faqs/res/findit.html
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/
