MyStruct <- list(list(CRmap = rnorm(50), xy = 1:50), list(CRmap = rnorm(50), xy = 51:100))
I wonder if it would be possible to extend indexing to accept lists. For example: MyStruct[[c(1, 2)]] extracts level1[1] and level2[2], so if the vector was a list, perhaps MyStruct[[list(c(1, 2), 2)]] ## level1[1:2], level2[2] In any case, I do not see a way presently that avoids lappy, but within that limitation, this is slightly simpler: lapply(MyStruct, `[`, "xy") Josh On Wed, Nov 17, 2010 at 6:56 AM, Ivan Calandra <ivan.calan...@uni-hamburg.de> wrote: > I understand now! > But I don't know of any easy way to do it. > > You would expect that something like these would work: > Mystruct[[1:2]][["xy"]] ## but error: subscript out of bounds, which makes > sense because "[[" accept only a single subscript > Mystruct[1:2][["xy"]] ## but NULL, which makes sense because "[" keeps > the upper elements, not only what is within Mystruct[1] and Mystruct[2] (not > sure I've stated right, but I hope you understand). > > I usually prefer using "[[" or "[" instead of "$" because you can use > indexes, which is better to vectorize or loop. > > So the only solution I've found (maybe someone here might give us a better > answer) is: > lapply(Mystruct, FUN=subset, select=xy) > or > lapply(Mystruct, FUN=subset, subset=whatever, select=xy) > if you also want to subset some specific rows > > HTH, > Ivan > > > > Le 11/17/2010 15:26, Alaios a écrit : >> >> It seems that I am confusing something: >> >> List of 50 >> $ :List of 2 >> ..$ CRmap: logi [1:100, 1:100] NA NA NA NA NA NA ... >> ..$ xy : num [1:2] 21 11 >> $ :List of 2 >> ..$ CRmap: logi [1:100, 1:100] NA NA NA NA NA NA ... >> ..$ xy : num [1:2] 80 68 >> >> >> >> --- On *Wed, 11/17/10, Ivan Calandra /<ivan.calan...@uni-hamburg.de>/* >> wrote: >> >> >> From: Ivan Calandra <ivan.calan...@uni-hamburg.de> >> Subject: Re: [R] Give me all operator >> To: r-help@r-project.org >> Date: Wednesday, November 17, 2010, 2:05 PM >> >> Well, without knowing what is the structure of Mystruct.Map and >> Mystruct.xy, it's really difficult to know how to help you. >> And what is Mystruct by the way!? >> Could you send us the output from dput(your_objects) and/or >> str(your_objects)? >> >> I think you're really confused about the structure of your >> objects. You >> probably need to read more stuff about that! >> >> Ivan >> >> Le 11/17/2010 14:56, Alaios a écrit : >> > Thanks a lot for your helpful answer. >> > In my case now I have implemented some "struct" with the following >> > structure >> > Mystruct.Map >> > Mystruct.xy >> > >> > If I do Mystruct[2].$xy I get correctly the xy values of the >> second item. >> > >> > I want now to print all the $xy fields of the Mystruct[[]] >> > I tried >> > Mystruct[data.frame(a=1:5)]]$xy which returns the following message: >> > >> > invalid subscript type 'list' >> > >> > >> > I would like to thank you again for your support >> > Regards >> > Alex >> > >> > --- On *Wed, 11/17/10, Ivan Calandra >> /<ivan.calan...@uni-hamburg.de >> </mc/compose?to=ivan.calan...@uni-hamburg.de>>/* >> > wrote: >> > >> > >> > From: Ivan Calandra <ivan.calan...@uni-hamburg.de >> </mc/compose?to=ivan.calan...@uni-hamburg.de>> >> > Subject: Re: [R] Give me all operator >> > To: r-help@r-project.org </mc/compose?to=r-h...@r-project.org> >> > Date: Wednesday, November 17, 2010, 1:44 PM >> > >> > Hi Alex, >> > >> > Is that what you're looking for: >> > > df <- data.frame(a=LETTERS[1:5], b=rnorm(5)) >> > > df >> > a b >> > 1 A -0.2401323 >> > 2 B -0.9414998 >> > 3 C 0.4289836 >> > 4 D 1.9802749 >> > 5 E -0.6993612 >> > > df[3,2] >> > [1] 0.4289836 >> > > df[3,] >> > a b >> > 3 C 0.4289836 >> > > df[,2] >> > [1] -0.2401323 -0.9414998 0.4289836 1.9802749 -0.6993612 >> > > df[,2, drop=FALSE] >> > b >> > 1 -0.2401323 >> > 2 -0.9414998 >> > 3 0.4289836 >> > 4 1.9802749 >> > 5 -0.6993612 >> > >> > See ?"[" for help. In short, in R you use "[", not brackets >> as in >> > matlab >> > (from your example, I've never used it). You don't need the >> ":", you >> > just don't write anything in R. >> > >> > Ivan >> > >> > Le 11/17/2010 14:34, Alaios a écrit : >> > > Hello is there in R any operator that give you all the data of a >> > matrix >> > > for example in matlab >> > > >> > > x(2,3) returns the 2ndth row and 3rdth column >> > > x(2,:) returns all the columns of the 2nd row. >> > > >> > > In R now I would like to print all the >> > > >> > > CRagent[[i]][2] >> > > >> > > >> > > CRagent[[:]][2] doesnot work of course. Other option is to >> > make a loop with an index i that spans from 1:last element of >> > CRagent[[]] but this is not that optimal. >> > > >> > > I would like to thank you in aavance for your help >> > > Best Regards >> > > Alex >> > > >> > > >> > > >> > > >> > > [[alternative HTML version deleted]] >> > > >> > > >> > > >> > > ______________________________________________ >> > > R-help@r-project.org </mc/compose?to=r-h...@r-project.org> >> </mc/compose?to=r-h...@r-project.org >> </mc/compose?to=r-h...@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 >> </mc/compose?to=ivan.calan...@uni-hamburg.de> >> > </mc/compose?to=ivan.calan...@uni-hamburg.de >> </mc/compose?to=ivan.calan...@uni-hamburg.de>> >> > >> > ********** >> > http://www.for771.uni-bonn.de >> > http://webapp5.rrz.uni-hamburg.de/mammals/eng/mitarbeiter.php >> > >> > ______________________________________________ >> > R-help@r-project.org </mc/compose?to=r-h...@r-project.org> >> </mc/compose?to=r-h...@r-project.org >> </mc/compose?to=r-h...@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 >> </mc/compose?to=ivan.calan...@uni-hamburg.de> >> >> ********** >> http://www.for771.uni-bonn.de >> http://webapp5.rrz.uni-hamburg.de/mammals/eng/mitarbeiter.php >> >> ______________________________________________ >> r-h...@r-project.org </mc/compose?to=r-h...@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 > > ______________________________________________ > 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. > -- Joshua Wiley Ph.D. Student, Health Psychology University of California, Los Angeles http://www.joshuawiley.com/ ______________________________________________ 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.
