Hi Rob Williams I think it is one way of you do the job. Cheers,
miltinho astronauta brazil my.df<-data.frame(cbind(data=sample(c("mon","sat","sun"), 20, replace=T), values=rnorm(20))) my.df$values<-as.numeric(my.df$values) data.weigth<-read.table(stdin(), head=T, sep=",") data,weigth mon,0.91 sat,1.21 sun,1.22 data.weigth data.merge<-merge(my.df, data.weigth, by.x="data", by.y="data", all=T) data.merge$values.weigth<-data.merge$values*data.merge$weigth data.merge On 7/23/08, Robin Williams <[EMAIL PROTECTED]> wrote: > > Hi all, > > Again I have searched the net and so on, without finding an answer to this > surely simple problem. A short bit of code would be appreciated. > > I have a object named `data' with the following column headings. > > Date, maxitemp, minitemp, admissions, d.o.w. > > Where d.o.w. is day of the week, written "Sun" "Mon" etc. > > I just need to scale the Monday admissions by 0.91, the Saturday > admissions by 1.21 and the Sunday admissions by 1.22. So basically what I > want is: > > If d.o.w. == "Sat" > > Multiply Sat admissions by 1.21. > > (Now do I need an else statement here, or can I just do another) > > If d.o.w. == "Sun" > > Multiply "Sun" admissions by 1.22 > > (and finally) > > If d.o.w. == "Mon" > > Multiply Monday admissions by 0.91. > > Else do nothing. > > I assume in my code I need to specify that I am using the data.frame > `data', so do I need to write things like > > If(data[d.o.w.]=="Mon") > > I would then like to round the new admissions to integers (I assume I just > use round(data$admissions)), and output the new data to another csv file. > > I could of course do this in excel but I will need to extend this type of > idea in the future so I would like to master it in R. > > Many thanks for any help/code. > > Robin Williams. > > > [[alternative HTML version deleted]] > > ______________________________________________ > 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. > [[alternative HTML version deleted]] ______________________________________________ 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.