Hi r-help-boun...@r-project.org napsal dne 30.03.2010 18:46:35:
> Hello, > > Thomas Jensen wrote: > > Dear R-list, > > > > Sorry for spamming the list lately, I am just learning the more advanced > > aspects of R! > > > > I have some data that looks like this: > > > > Out Country1 Country 2 Country 3 ... CountryN > > 1 1 1 1 1 > > 0 1 1 0 1 > > 1 1 0 1 0 > > > > Don't paste data like this to the list. Use ?dput to create an easy to > use data.frame that users of the list can input with one R command. You > will most likely get help very quickly at that point since our data will > match your's exactly. > > > I want to create a new variable that counts the number of zeros in every > > row whenever Out is equal to 1, and else it is a zero, so it would look > > like this: > > > > new_var > > 0 > > 0 > > 2 > > > > I have tried the following: > > > > for (i in length(Out)){ > > if (Out == 1) {new_var <- sum(dat[i,] != 1)} > > else {new_var <- 0} > > } > > > > but this gives me an error message. > > I have not tested any of this, but I'm guessing something like the > following would work. Assume your data.frame is called df. > > #NOT TESTED > tmp <- apply(df, 1, function(x) sum(x == 0)) > df$new_var <- ifelse(df$Out == 1, tmp, 0) Maybe this can work too df$new_var <- rowSums(df[, -1] ==0) * (df$Out==1) Regards Petr > > See ?apply and ?ifelse . > > > > > > > > Best, Thomas > > > > ______________________________________________ > > 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. ______________________________________________ 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.