the code returns Error: do.call("[", c(list(z),1,1,ix)) #Error in 1:24[1, 1, 1:3, 1:4] : incorrect number of dimensions May be something is missing. A.K.
----- Original Message ----- From: Bert Gunter <gunter.ber...@gene.com> To: Martin Ivanov <tra...@abv.bg> Cc: r-help@r-project.org Sent: Sunday, May 26, 2013 10:43 AM Subject: Re: [R] avoiding eval parse with indexing Martin: Well, assuming I understand, one approach would be to first get the dim attribute of the array and then create the appropriate call using that: > z <- array(1:24,dim=2:4) > d <- dim(z) > ix <-lapply(d[-c(1,1)],seq_len) > do.call("[", c(list(z),1,1,ix)) [1] 1 7 13 19 Is that what you want? -- Bert On Sun, May 26, 2013 at 6:56 AM, Martin Ivanov <tra...@abv.bg> wrote: > Hello, > I would like to get an advice on how the notorious eval(parse()) construct > could possibly > be avoided in the following example. I have an array x, which can have > different number of dimensions, > but I am only interested in extracting, say, the first element of the first > dimension. Currently I achieve this > in this way: > > eval(parse(text=paste0("x[1", paste(rep(", ", length(dim(x)) - 1), > collapse=""), "]"))) > > Is it possible to avoid the eval parse here? How? > > Best regards, > > Martin > > ______________________________________________ > 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. -- Bert Gunter Genentech Nonclinical Biostatistics Internal Contact Info: Phone: 467-7374 Website: http://pharmadevelopment.roche.com/index/pdb/pdb-functional-groups/pdb-biostatistics/pdb-ncb-home.htm ______________________________________________ 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.