Re: st: How to Calculate A Variable of Maximum Values up to each of the 114 periods in my sample?

[Nick Cox <njcoxstata@gmail.com>]

Getting the maximum so far is an FAQ on the Stata website. See also a  
function in -egenmore- (SSC).

Nick

On 14 Dec 2012, at 16:53, Yuval Arbel <yuval.arbel@gmail.com> wrote:

> Dear Statalisters,
>
> I am trying to generate a variable, which will give me the maximum
> value of another variable (reduct_per) up to each of the 114 periods
> in my sample.
>
> Note that the function -max- works only with -egen-, namely it creates
> a constant maximum, and not a running maximum..
>
> I therefore wrote the following set of commands:
>
> by appt: egen y=max(reduct_per)
> by appt: gen max=reduct_per if time_index==0
> by appt: replace max=reduct_per if reduct_per==y
> by appt: replace max=reduct_per[_n-1] if reduct_per<=reduct_per[_n-1]
> & max==. & time_index==1
> by appt: replace max=reduct_per if max==. & time_index==1
>
> by appt: replace max=max[_n-1] if reduct_per<=max[_n-1] & max==. &
> time_index==2
> by appt: replace max=reduct_per if max==. & time_index==2
>
> by appt: replace max=max[_n-1] if reduct_per<=max[_n-1] & max==. &
> time_index==3
> by appt: replace max=reduct_per if max==. & time_index==3
>
> by appt: replace max=max[_n-1] if reduct_per<=max[_n-1] & max==. &
> time_index==4
> by appt: replace max=reduct_per if max==. & time_index==4
>
> by appt: replace max=max[_n-1] if reduct_per<=max[_n-1] & max==. &
> time_index==5
> by appt: replace max=reduct_per if max==. & time_index==5
>
> by appt: replace max=max[_n-1] if reduct_per<=max[_n-1] & max==. &
> time_index==6
> by appt: replace max=reduct_per if max==. & time_index==6
>
> and so on. My question is whether there is a more elegant way to
> generate this variable. More specifically I would like to know
> whether I need to write a loop, and if so how would I write it so that
> I don't have to repeat the last two commands for 114
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