st: Calculating a maximum out of a subset in a sequence

[<benignor@javeriana.edu.co>]

I am the original poster of this question.

I found a very inelegant solution:

	. gen index = 1 if C4NAIVC ~=.|CD4MEMC ~=.
	(252 missing values generated)

	. sort patid WEEK1

	. by patid: egen obsnum = seq()

	. by patid: replace index = . if (index[_n-1] ==. & obsnum >1)
	(191 real changes made, 191 to missing)

	. by patid: egen LatestNaive = max(WEEK1) if index ==1
	(443 missing values generated)

	. by patid: replace LatestNaive=LatestNaive[_n-1] if LatestNaive ==.
	(395 real changes made)

	. drop index

Surely there is a less cumbersome way to achieve the same result?

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