Do not worry, I found the solution. I had a list, as follows :
x <- list() x$i <- 5 x$j <- 9 x$k <- 15 names(x$i) <- "a" names(x$j) <- "b" names(x$k) <- "b" And I wanted to obtain a list, as follows : $a i 5 $b j k 9 15 My solution : n <- sapply(x, names) m <- sapply(x, c, use.names = FALSE) tapply(m, n, c) Thanks for answers. Carlos 2010/8/11 Wu Gong <w...@mtmail.mtsu.edu>: > Hi Carlos, > > I don't know what kind of data you really have. It's would be helpful if you > give a sample data. You really don't need to use sapply. > > R can assign names through vectors: > > names(y) <- names(x) > > Or: > > names(y) <- c("NameA","NameB") > > Regards, > > Wu > > > > ________________________________________ > From: Carlos Petti [carlos.pe...@gmail.com] > Sent: Wednesday, August 11, 2010 5:39 AM > To: Wu Gong > Cc: r-help@r-project.org > Subject: Re: [R] How to invert a list ? > > Or rather : > n <- sapply(x, function(i) names(i)) > tapply(x, n, names) > > 2010/8/11 Carlos Petti <carlos.pe...@gmail.com>: >> A beginning of solution... >> >> n <- sapply(x, function(i) names(i)) >> tapply(x, n, c) >> >> 2010/8/11 Carlos Petti <carlos.pe...@gmail.com>: >>> Thanks. >>> >>> On the other hand, >>> I try to obtain the same result but from this list : >>> >>> x <- list() >>> x$i <- 5 >>> x$j <- 9 >>> x$k <- 15 >>> names(x$i) <- "a" >>> names(x$j) <- "b" >>> names(x$k) <- "b" >>> >>> Thanks in advance, >>> Carlos >>> >>> 2010/8/10 Wu Gong <w...@mtmail.mtsu.edu>: >>>> >>>> Hi Carlos, >>>> >>>> I give a handmade code, hope it helps. >>>> >>>> y <- list() >>>> y$a <- a >>>> y$b <- c(b,c) >>>> names(y$a) <- "i" >>>> names(y$b) <- c("j","k") >>>> >>>> >>>> Carlos Petti wrote: >>>>> >>>>> a <- 5 >>>>> names(a) <- "a" >>>>> b <- 9 >>>>> names(b) <- "b" >>>>> c <- 15 >>>>> names(c) <- "c" >>>>> x <- list("i" = a, "j" = b, "j" = c) >>>>> >>>> >>>> >>>> ----- >>>> A R learner. >>>> -- >>>> View this message in context: >>>> http://r.789695.n4.nabble.com/How-to-invert-a-list-tp2320108p2320433.html >>>> Sent from the R help mailing list archive at Nabble.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. >>>> >>> >> > ______________________________________________ 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.