Hi What about some example data? I presume you could use some
apply, tapply, aggregate or similar function but without knowing what you **really** want to do and how your previous attempts failed it is hard to give any definite answer. e.g. mydf<-data.frame(year=sample(1:4,100,rep=T), student=sample(letters[1:4],100, rep=T), result=runif(100)) aggregate(mydf$result,list(year=mydf$year,student=mydf$student), mean) year student x 1 1 a 0.4026579 2 2 a 0.4690311 ... 15 3 d 0.5316301 16 4 d 0.4401949 > HTH Petr On 14 Apr 2006 at 0:09, Brian Quinif wrote: Date sent: Fri, 14 Apr 2006 00:09:32 -0400 From: "Brian Quinif" <[EMAIL PROTECTED]> To: [email protected] Subject: [R] another very simple loop question > I have a dataset with 4 years of students, and normally I want to > estimate things using each individual year, so I have a for loop as > follows > > for (i in 1:4){} > > However, the only way I know how to calculate estimates using all four > years of data is to put the estimations outside of the loop. Is there > anyway to make a for loop that uses all four years at once, then uses > each individual year? > > Thanks, > > BQ > > ______________________________________________ > [email protected] mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! > http://www.R-project.org/posting-guide.html Petr Pikal [EMAIL PROTECTED] ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
