Hello On Fri, Apr 8, 2011 at 12:38 AM, Raoni Rodrigues <caciquesamu...@gmail.com> wrote: > Hello all! > > I have a data frame with nine variables and 293 cases. (attached goes > the csv file). > The CSV didn't get through so it's difficult to replicate your example. Please post the output of: str(cpue)
> I need to calculate a index using the sum of one variable (N) divided > by the length of other variable (Fisherman), but for each day (Date). > > I tried to use that codes: > > by (cpue, cpue$Date, function (x) sum (cpue$N)/length(cpue$Fisherman)) > [..] > In both codes, as result, I received the same value for all Date > value. And, oddly, this result is the value of calculation for all > data frame, as I used just: > > sum (cpue$N)/length(cpue$Fishermans) > >From the code above, this is expected since in the function() statement you use the entire df (cpue) and not the subset (x). Try this: by (cpue, cpue$Date, function (x) sum (x$N)/length(x$Fisherman)) > Sorry for the basic question, but I worked on this simple code all day > and can't do it work out! And have no idea why... > > I'm using R 2.11 in Windows XP. > It is often a good a idea to post the output of sessionInfo() Regards Liviu > Since now, thanks for the attention and all help, > > Best, > > Raoni > > ______________________________________________ > 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. > > -- Do you know how to read? http://www.alienetworks.com/srtest.cfm http://goodies.xfce.org/projects/applications/xfce4-dict#speed-reader Do you know how to write? http://garbl.home.comcast.net/~garbl/stylemanual/e.htm#e-mail ______________________________________________ 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.
