Re: st: advance a -foreach- loop?

[Jeph Herrin <junk@spandrel.net>]

Austin, Nick, thanks for the replies.

I think I should have been more specific about my list
of variables. I am processing several input files with this,
and in each all I know about the variables of interest is that
they have a given prefix. So in practice

  local biglist = "prfx_*"

Ie, I oversimplified in my example; the variables are actually

  prfx_payor_1
  prfx_payor_2
  prfx_payor_3
  ... etc

There are hundreds of variables in each file, and it would be far
more time consuming to go through and group them, especially as
I will be rerunning this routinely on files that someone else is
producing, with the variables changing potentially each time.

Also, because of the number of variables, I think expanding into
a macro and then indexing over the words will not work because of
the limit on macro length (right?).

However, I may have to next my loop inside another, and do some
preprocessing of -biglist- first.

thanks,
Jeph



Austin Nichols wrote:
> Jeph Herrin <junk@spandrel.net>:
> Can you not use -else- here?  I.e.
>  foreach V of varlist `biglist' {
>   gettype(`V')
>   if `type'=="M" {
>    <do stuff>
>   }
>   else {
>    <do other stuff>
>   }
>  }
>
> If you did want to reference variables by their number, and did -keep
> `biglist'- first, you can refer to word `i' of `biglist' to get the
> ith variable (see "Macro extended functions for parsing" in help
> extended_fcn).
>
> BTW, it might be more efficient to move the type "M" variables into a
> separate macro to process separately, depending on how you are
> choosing to handle all the variables in a particular group, e.g.
> payor_1-payor_6.  E.g.
>
>  foreach V of varlist `biglist' {
>   gettype(`V')
>   if `type'=="M" {
>    <make list of variables related to `V' e.g. payor_1-payor_6>
>    <and put the list in local `thislist' >
>    loc mlist `" `mlist' "`thislist'" "'
>   }
>   else {
>    <do other stuff>
>   }
>  }
>  foreach V of varlist `mlist' {
>   <now operate on each group of related vars>
>  }
>
> On Tue, May 13, 2008 at 3:45 PM, Jeph Herrin <junk@spandrel.net> wrote:
> > I have hundreds of variables that I need to loop through
> > and process. Some of them are grouped together because they
> > represent different options that are not mutually exclusive;
> > for example, "Insurance type: check all that apply:" has
> > results stored in:
> >
> >   payor_1
> >   payor_2
> >   payor_3
> >   payor_4
> >   payor_5
> >   payor_6
> >
> >
> > I have a datum -type- associated with each that tells me it is part of a
> > "multiselect" (sic) question, so when I loop through all my variables:
> >
> >  foreach V of varlist `biglist' {
> >        gettype(`V')
> >        if `type'=="M" {
> >                <do stuff>
> >        }
> >        .
> >        .
> >        .
> >  }
> >
> > The ... handles every other types of variable. However, when I
> > <do stuff> I'd like to handle all the variables in that particular
> > group, eg, payor_1-payor_6. I can do this, but then I need to advance
> > the -foreach- to the variable *after* payor_6.
> >
> > One thought I had was to reference the variables by their number, which
> > is available via -describe, number- (I'd have to -keep `biglist'- first)
> > but I'm not sure how to refer to a variable by its number, and can't
> > find any info on how to do so.
> >
> > Does anyone see how to make this idea - or any other- work so I can skip
> > ahead in a -foreach- loop?
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