On Thu, Sep 11, 2008 at 3:37 AM, Kunzler, Andreas <[EMAIL PROTECTED]> wrote: > Dear List, > > I ran into some problems with time-series-Data. > > Imagine a data-structure where observations (x) of test attendants (i) are > made a four times (q) a year (y). The data is orderd the following way: > I y q x > 1 2006 1 1 > 1 2006 3 1 > 1 2006 4 1 > 1 2007 1 1 > 1 2007 2 1 > 1 2007 3 1 > 1 2007 4 1 > 2 2006 1 1 > 3 2007 1 1 > 3 2007 2 1 > > I am looking for a way to count the attendants that at least have attendend > one time a year. In this case 2 persons, because i=2 has no observation in > 2007. >
Don't you mean 1 person, not 2 persons, since - attendant 1 appears in both years but - attendant 2 appears only in 2006 - attendant 3 appears only in 2007 so only attendant 1 appears in both years, i.e. 1 person. Assuming DF is your data frame: u <- unique(DF[1:2]) with(u, sum(tapply(y, I, length) == length(unique(y)))) # 1 > I thought about creating a subset with the duplicate function. But I can't > find a way to control (i) and (y). > > subset(data, !duplicated(i[y])) > > Thanx so much > > Andreas Kunzler > ____________________________ > Bundeszahnärztekammer (BZÄK) > Chausseestraße 13 > 10115 Berlin > > Tel.: 030 40005-113 > Fax: 030 40005-119 > > E-Mail: [EMAIL PROTECTED] > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
