As wolski/Eryk's example shows, it seems that "[[" for lists accepts abbreviations, whereas "[" does not. Is this intended? (This is a difference from S-plus - both "[" and "[[" for lists accept abbreviations in S-plus (V6.1 for Windows at least.)
I couldn't find any mention of this difference in regards to accepting abbreviations in either ?"[" or section 6.1 of the Introduction to R, or in the R Language Manual, or in the R Reference Manual. [As an aside, I'd rather that the subset operators didn't accept abbreviations at all,but ...] The name returned by "[" for a non-existent element of a list also seems of dubious correctness. > list(abc=123)[["a"]] [1] 123 > list(abc=123)["a"] $"NA" NULL > list(abc=123)$a [1] 123 > version _ platform i386-pc-mingw32 arch i386 os mingw32 system i386, mingw32 status major 1 minor 6.2 year 2003 month 01 day 10 language R > At Monday 04:54 PM 3/24/2003 +0100, you wrote: >wolski wrote: >>Hello! >>let: >>test<-1:3 >>list(test) >>names(test)<-c("X11","X12","Y23") >> >>>test[["Y2"]] >>3 >>I had assumed that the names in a list are like a keys in a hash. >>Therefore i thought that no value should be returned. >>The behavior of: >> >>>test["Y2"] >><NA> NA >>is as i expected. >> >>Should it be as it is? How is the definition of [[]] and []? > >No! See "An Introduction to R", Section 6.1: >"The names of components may be abbreviated down to the minimum number of letters >needed to identify them uniquely. Thus Lst$coefficients may be minimally specified as >Lst$coe and Lst$covariance as Lst$cov." > >Uwe Ligges > >______________________________________________ >[EMAIL PROTECTED] mailing list >https://www.stat.math.ethz.ch/mailman/listinfo/r-help ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help