Jeph Herrin <[email protected]> :
Stata/SE can put 1,081,511 characters in a local macro, so that
constraint may not be binding. To be clear, when I proposed moving the
groups of variables into a separate macro and dealing with the groups
in a separate loop, I took it as read that you had a method for
constructing such groups, since you wrote "I'd like to handle all the
variables in that particular group... I can do this, but then I need
to advance the -foreach-"
The reason for moving the groups of variables into a separate macro
and dealing with the groups in a separate loop is: suppose for any
given variable v, you can identify a group of 6 related variables m_v
(including v itself) and process all 6 inside the loop. When you
reach the next variable in group m_v, you will repeat this process,
making the whole thing take 6 times as long as it should. OTOH, the
construction of a long local macro containing groups should take a
negligible amount of time, and then the groups can be looped over one
by one.
On Wed, May 14, 2008 at 9:05 AM, Jeph Herrin <[email protected]> wrote:
>
> 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 <[email protected]>:
>> 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 <[email protected]> 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?
>>
>> *
>> * For searches and help try:
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>>
> *
> * 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/
