> -----Original Message----- > From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On > Behalf Of JulioSergio > Sent: Thursday, November 10, 2011 2:59 PM > To: r-h...@stat.math.ethz.ch > Subject: Re: [R] Named components in a list > > Jeff Newmiller <jdnewmil <at> dcn.davis.ca.us> writes: > > > > > >Well, Bert, then the manual where I found the example must be wrong. It > > >is: > > > > > >http://cran.r-project.org/doc/manuals/R-intro.html#Constructing-and- > modifying- > > >lists > > > > > >And textually it says: > > > > > >Lists, like any subscripted object, can be extended by specifying > > >additional > > >components. For example > > > > > > > Lst[5] <- list(matrix=Mat) > > > > It may be true that the example is susceptible to misinterpretation, but > > that > is certainly what you are doing. > > > > If there were four items in Lst, then after this statement there will be > > five, > which means the list has been extended. > > > > The item that has been added is an unnamed list. The arguments to any object > creation function always > > describe the contents of that object, not the name by which you refer to the > object. > > > > If you wanted the next item in Lst to be a named list, you would refer to it > by name when you assigned it: > > > > Lst["mymatrix"] <- list (matrix=Mat) > > > > But if you wanted to merge the elements of two lists you would concatenate: > > > > Lst <- c(Lst, list(matrix = Mat)) > > > > > > Yeah, all that you say is right, but my point is, then what is the use of > puting this example in the manual (tutorial), because the same result could > be obtained by simply writing: > > > Lst[5] <- Mat
That version is wrong. It causes a warning and results in the same thing as Lst[5] <- list(Mat[1]) You need either Lst[5] <- list(Mat) or Lst[[5]] <- Mat to make the 5th component of Lst the matrix Mat. If you want the component to named "matrix" then use one of Lst["matrix"] <- list(Mat) or Lst[["matrix"]] <- Mat Bill Dunlap Spotfire, TIBCO Software wdunlap tibco.com > > istead of > Lst[5] <- list(matrix=Mat) ? > > ______________________________________________ > 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.