On Fri, 12 Aug 2005, Kjetil Brinchmann Halvorsen wrote: > Prof Brian Ripley wrote: > >> I don't know if you can read your message, but I find it exceedingly >> difficult and there seem to be several typos. Please use the space and >> return keys ... and only send a message once. >> >> You problem is perhaps that you are not looking at the data frame, but at >> the variable in the workspace. attach()ing data frames is convenient but >> error-prone (as you have found). rm(new.variable) should solve this, but >> it is better to cultivate a different style. For example >> >> with(data.frame1, { >> # commands to create value >> data.frame1$new.variable <- value >> }) >> data.frame3 <- na.omit(data.frame1) >> >> > That cannot possible work,
No, it's just a sketch of a style. > as assignment within with is local to with's environment. I have used > superassigmnent for this (<<-), but that cannot possible be a good > style? I intended that the changed object be returned: so for example test <- with(test, {test$c <- 1:5; test}) does work. What I really meant to write (and had tested) could be sketched as value <- with(data.frame1, { # commands to create value }) data.frame1$new.variable <- value data.frame3 <- na.omit(data.frame1) but cut-and-paste got two lines out of order. > Look at the following: > >> test <- data.frame( a=1:5, b=1:5) >> test > a b > 1 1 1 > 2 2 2 > 3 3 3 > 4 4 4 > 5 5 5 >> with(test, test$c <- 1:5) >> test > a b > 1 1 1 > 2 2 2 > 3 3 3 > 4 4 4 > 5 5 5 >> with(test, test$c <<- 1:5) >> test > a b c > 1 1 1 1 > 2 2 2 2 > 3 3 3 3 > 4 4 4 4 > 5 5 5 5 > > So what is the best style her? > > Kjetil -- Brian D. Ripley, [EMAIL PROTECTED] Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595 ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html