Hi Dennis, What is the problem with using eval(parse(text=...))? Is there a reason why not to use it? Of course, in that case, "list" within save() is much easier and works perfectly.
In any case, thanks for your explanations :) Ivan Le 5/20/2010 10:26, Dennis Murphy a écrit : > Hi: > > On Thu, May 20, 2010 at 12:43 AM, Ivan Calandra > <ivan.calan...@uni-hamburg.de <mailto:ivan.calan...@uni-hamburg.de>> > wrote: > > Thanks to all of you for your answers! > > Peter's is definitely the easiest :) > for (i in 1:4) { > temp <- data.frame(a=(i+1):(i+10), b=LETTERS[(i+1):(i+10)]) > filename <- paste("file", i, sep="") > assign(filename, temp) > save(list=c(filename), file=paste(filename, ".rda", sep="")) > } > > > > Tao, I don't understand why you have backslashes before "file" and after > > .rda. I guess it's something about regular expression, but I'm still > very new to it. > eval(parse(text=paste("save(file", i, ", file=\"file", i, ".rda\")", > sep=""))) > > > eval(parse(text = ...)) is necessary sometimes, but usually not. This > is one of > the 'not' cases. Re your question, the backslash is used to escape the > quote > within the quote so that it is rendered properly when parsed/evaluated. > > > Jorge, your solution does not work... I've just copy/pasted your code. > My second great weakness is with the apply() family. So maybe I > have to > adjust some part of the code to my needs, but I'm unable to do it. > i <- 1:4 > sapply(i, function(i) { > x <- data.frame(a=(i+1):(i+10), b=LETTERS[(i+1):(i+10)]) > save(x, file = paste("file", i, ".rda", sep="")) > } ) > > > I tried a variation on this solution, and discovered that whenever you > load > a .rda file, the name of the object is the same in all of them. It > 'works' in the > sense that the right object is saved to each of the file*.rda; > however, when > loaded, all the objects have the same name x, so in the end it doesn't > really > work. > > Peter figured out that saving the object as a list was the key - that > way, > the name of the object saved is the value of filename (file*) so that > when it > is loaded back in, the object names are distinct. > > A more interesting question than it appeared at first... > > Dennis > > > Anyway, everything's now fine! > Thanks again. > Ivan > > > Le 5/19/2010 20:29, Jorge Ivan Velez a écrit : > > Hi Ivan, > > > > How about this? > > > > i <- 1:4 > > sapply(i, > > function(i){ > > x <- data.frame(a=(i+1):(i+10), b=LETTERS[(i+1):(i+10)]) > > save(x, file = paste("file", i, ".rda", sep="")) > > } > > ) > > > > HTH, > > Jorge > > Le 5/19/2010 22:20, Peter Ehlers a écrit : > > On 2010-05-19 12:05, Shi, Tao wrote: > >> Ivan, > >> > >> Try this: > >> > >> eval(parse(text=paste("save(file", i, ", file=\"file", i, > >> ".RData\")", sep=""))) > >> > >> ...Tao > >> > > > > Or just use 'list=' like this: > > > > for (i in 1:4) { > > temp <- data.frame(a=(i+1):(i+10), b=LETTERS[(i+1):(i+10)]) > > filename <- paste("file", i, sep="") > > assign(filename, temp) > > save(list=c(filename), file=paste(filename, ".rda", sep="")) > > } > > > > -Peter Ehlers > > > >> > >> > >> ----- Original Message ---- > >>> From: Ivan Calandra<ivan.calan...@uni-hamburg.de > <mailto:ivan.calan...@uni-hamburg.de>> > >>> To: r-help@r-project.org <mailto:r-help@r-project.org> > >>> Sent: Wed, May 19, 2010 7:56:44 AM > >>> Subject: [R] save in for loop > >>> > >>> Dear users, > >> > >> My problem concerns save() within a for loop. > >> Here is my > >>> code: > >> > >> for (i in 1:4) { > >> temp<- data.frame(a=(i+1):(i+10), > >>> b=LETTERS[(i+1):(i+10)]) > >> filename<- paste("file", i, sep="") > >> > >>> assign(filename, temp) > >> save(filename, file=paste(filename, ".rda", > >>> sep="")) > >> } > >> > >> As you can see, save() doesn't work as I would like: (1) > >>> the object saved is called "filename" (instead of "file1", > "file2", > >>> etc), and > >>> (2) it of course contains only the name (as character) instead > of the > >>> data.frame > >> > >> How can I fix it? > >> > > [snip] > > > > -- > Ivan CALANDRA > PhD Student > University of Hamburg > Biozentrum Grindel und Zoologisches Museum > Abt. Säugetiere > Martin-Luther-King-Platz 3 > D-20146 Hamburg, GERMANY > +49(0)40 42838 6231 > ivan.calan...@uni-hamburg.de <mailto:ivan.calan...@uni-hamburg.de> > > ********** > http://www.for771.uni-bonn.de > http://webapp5.rrz.uni-hamburg.de/mammals/eng/mitarbeiter.php > > > [[alternative HTML version deleted]] > > > ______________________________________________ > R-help@r-project.org <mailto: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. > > -- Ivan CALANDRA PhD Student University of Hamburg Biozentrum Grindel und Zoologisches Museum Abt. Säugetiere Martin-Luther-King-Platz 3 D-20146 Hamburg, GERMANY +49(0)40 42838 6231 ivan.calan...@uni-hamburg.de ********** http://www.for771.uni-bonn.de http://webapp5.rrz.uni-hamburg.de/mammals/eng/mitarbeiter.php [[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.
