Re: st: Replacing values

[Roberto Ferrer <refp16@gmail.com>]

Thanks Nick.

The second solution worked.

The first does not because it adds up the values of pop_region by
state and district. Substituting total() for min(), max(), mean(),
etc. works since the values involved are constants:

egen pop2005 = min(pop_region / (year == 2005)), by(state district)

(Trying to get my hands on the reference you gave.)

Thanks again.

On Tue, Jul 9, 2013 at 10:32 PM, Nick Cox <njcoxstata@gmail.com> wrote:
> egen pop2005 = total(pop_region / (year == 2005)), by(state district)
> replace pop_region = pop2005 if missing(pop_region)
>
> In your example, this works
>
> bysort state district (year) : replace pop_region = pop_region[_N]
>
> For a review of technique see
> http://www.stata-journal.com/article.html?article=dm0055
> Nick
> njcoxstata@gmail.com
>
>
> On 9 July 2013 22:12, Roberto Ferrer <refp16@gmail.com> wrote:
>> For every possible year in the data, I want to replace the missing
>> values of the variable pop_region using the corresponding value of
>> variables state and district of year 2005. So the first value of
>> pop_region in the example
>> should be 25, the second 25, ..., the sixth 50, the eighth 62, etc.
>>
>> year  state  district  st_pop  pop_region
>> 1995   a         1           100         .
>> 1995   a         2           100         .
>> 1995   a         2           100         .
>> 1995   a         2           100         .
>> 1995   a         2           100         .
>> 1995   a         3           100         .
>> 1995   a         3           100         .
>> 1995   b         1           200         .
>> --------------------------------------------------------
>> 2005   a         1           100         25
>> 2005   a         2           100         25
>> 2005   a         3           100         50
>> 2005   a         3           100         50
>> 2005   b         1           200         62
>> 2005   b         1           200         62
>> 2005   b         1           200         62
>> 2005   b         1           200         62
>>
>> I tried this (and other stuff) which seems too involved for the task
>> and doesn't work of course:
>>
>> levelsof year, local(lyear)
>> levelsof state, local(lstate)
>> levelsof district, local(ldistrict)
>>
>> foreach y of local lyear {
>>     foreach s of local lstate {
>>         foreach r of local ldistrict {
>>              local reval = pop_region if yearobs==2005 & state==`s' &
>> district==`r'
>>              replace pop_region = `reval' if state == `s' & district == `r'
>>         }
>>     }
>> }
>>
>> Thanks.
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