Thank you, Dan. It works well.
Maoyong Fan
UCB
>You were almost there with return macro var r(r). This will
>evaluate to the number of categories of your tabulated variable.
>
>Just add that to your code:
>
>. local varlist_2 = "verbal_sat dum1-dum`r(r)'"
>
>. di "`varlist_2'"
>
>verbal_sat dum1-dum30
>
>Dan Blanchette
>Carolina Population Center UNC-CH
>
>>
>> Dear Statalist members,
>>
>> I met a small stata problem. Does anyone have a good way to do it?
>>
>> Problem:
>>
>> The subprogram is like this:
>>
>> load big data set
>> select small data set
>> generate dum
>> show how many dum variables are generated
>> loop to operate on each dum
>>
>> In total, there are over fifty such small subprograms, every small data set is different from the other.
>>
>> I have to check how many dums are there in the subprogram and put the number into loop. Everytime, I change the big dataset, I have to recheck the dum number and reinput the dum number into the loop.
>>
>> How can I let the stata do this automatically?
>>
>> Example of subprogram:
>>
>> use pdp_matching.dta, clear
>>
>> keep gender coalition_pool verbal_sat math_sat c32_lecture c32_times_taken c32_year c32_term c32_num_grade c32_math_98 c32_pdp_ids c32_pdp_ids_not_pass c32_slc_adjunct c32_slc_adjunct_not_pass
>>
>> drop if gender == .
>> drop if coalition_pool == .
>> drop if verbal_sat == .
>> drop if math_sat == .
>> drop if c32_lecture == .
>> drop if c32_year == .
>> drop if c32_term == .
>> drop if c32_num_grade == .
>>
>> keep if c32_num_grade < 5
>>
>> generate same_class = c32_year*100 + c32_term*10 + c32_lecture
>>
>> tabulate same_class, gen(dum)
>>
>> di r(r)
>>
>> local varlist_1 = "gender math_sat"
>> local varlist_2 = "verbal_sat dum1-dum30"
>>
>> Note: I have to input 30 by myself before!!! Can stata do this automatically?
>>
>> foreach var of local varlist_1 {
>> egen `var'_max = max(`var')
>> egen `var'_min = min(`var')
>> if `var'_max ~= `var'_min {
>>
>> local varlist_2 = "`varlist_2' `var'"
>> di "keep `var'"
>> }
>> else {
>> display "drop `var'"
>>
>> }
>> }
>> display "Finish dropping"
>>
>>
>>
>> Warm regards,
>>
>> Maoyong Fan
>>
>>
>>
>>
>>
>>
>
>
>*
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