Dear David
Thank you for your e-mail
I believe that equivalent to Stata egen tag is simply
df$tag <- df[!duplicated(df[c("station","week")]),]
I am not sure about
egen count
It might be something like
aggregate(station~week, df, function(x)sum(!is.na(x)), na.action = na.pass)
I made this question while making very first steps in R after actively using
Stata for 3 years. And I underestimated the extent of flexibility of R. But
after your answer on one of my previous questions I realized that I can use,
for instance mean(tapply(<sth>)) or table(<sth>)/<sth> right
away which is great
With best regards
Denis
----- Original Message ----
From: David Winsemius <dwinsemius at comcast.net>
To: Denis Kazakevich <den2042 at yahoo.com>
Sent: Sun, 23 January, 2011 17:56:53
Subject: Re: [R] Equivalent to Stata egen tag
On Jan 16, 2011, at 6:48 PM, Denis Kazakevich wrote:
> What are the R equivalents to the Stata command egen tag
> and
> egen count?
>
> egen station_week_tag = tag(station week)
I have looked at similar questions in the past and gone to the Stata online docs
and tried to make some sense of them and even posted an attempt at an answer.
The documents appeared to be to be fairly cryptic. Much more so that the R
documentation. I was somewhat snottily informed by experienced Stata users that
I had completely misunderstood the documentation and that egen was much more
rich an varied that I understood. So I've given answering Stata questions.
Given
the protean nature of the egen I think it's unrealistic of you to expect
that
just posting code will communicate what you intended.
--
David Winsemius, MD
Heritage Laboratories
West Hartford, CT