st: Need help for calculation across observations within variable

[Michael Stewart <michaelstewartresearch@gmail.com>]

HI,

I am looking to see if anyone could an efficient code than what I have
been using for a particular issues that I am dealing with

My Need

1)Create a variable which shows if the "year" is same or different by pat_name
2)Create a variable which shows number of distinct years ,per patient

My dataset structure is as follows

pt_name     year(string variable)
111             2009
111             2009
111             2009
111             2011
222             2009
222            2009
222            2010

My code is two step one
Step-1: bysort pt_name(year):  gen flag=_n==_N
Step-2:egen max=total(flag),by(pt_name)

Please let me know if there is an more efficient one step code


-- 
Thank you ,
Yours Sincerely,
Mike.
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