Terrific! Many thanks, Josh, you put me on the right path with the tip re dput and the remark about factors.
Using "stringsAsFactors=FALSE" in my read.table and then "IndexList <- c( unlist(seed_panel[ i, ]), rownames( Control[ j, ] ) )" did the trick. Your help is hugely appreciated. Thanks again! G On 18 August 2010 06:46, Joshua Wiley <jwiley.ps...@gmail.com> wrote: > Hi, > > I believe you are looking for ?unlist. Here is something that does > what I think you want with data that is my best guess at what yours is > like (if the data in seed_panel is stored as factor, you will probably > need to convert it first somehow). > >> seed_panel <- data.frame(V2 = "507D22", V3 = "518F15", stringsAsFactors = >> FALSE) >> Control <- matrix(1:4, ncol = 2, dimnames = list(c("505E01", "etc"), >> c("Col1", "Col2"))) >> >> unlist(c(seed_panel[1, ], rownames(Control)[1])) > V2 V3 > "507D22" "518F15" "505E01" > > As a future suggestion, doing something like > dput(head(your_data_name)) is a simple way to provide us with the > first few rows of your data. > > Cheers, > > Josh > > On Tue, Aug 17, 2010 at 10:36 AM, Gil Gamesh <games...@gmail.com> wrote: >> Apologies, I neglected to check that the email was plain text. Here is >> a the text of the previous email. >> >> >> Hello, >> >> I am trying to iteratively build a build a panel of variables to >> discriminate between two groups. >> >> My starting position is a matrix of experimental data and I have a function >> that will work through all pairs of variables and produce sensitivities, >> specificities and p-values for each pair and write it to a file (above >> particular cut-offs). >> >> I have a second function that will read that file in and use the pairs as a >> 'seed' adding a third variable from the original matrix and performing the >> same calculations and writing a new file. >> >> My aim is to iterate through this procedure five or six times. >> >> My difficulty is making the index vector to extract the values I need from >> the matrix of experimental data. >> >> The seed panel is a row in a data.frame: >> >> print(seed_panel[i,]) >> >> V2 V3 >> 1 507D22 518F15 >> >> >> and the variable to add to it is a rowname of the experimental matrix: >> >> print(rownames(Control[j,])) >> >> [1] "505E01" >> >> I haven't found a way to combine these three - I would like a vector >> c("507D22","518F15","505E01") - to subscript the matrix of experimental >> data. >> >> IndexList <- c(as.vector( seed_panel[ i, ], mode="any"), rownames( Control[ >> j, ] ) ) >> >> Gives: >> >> $V2 >> [1] 507D22 >> 18 Levels: 507D22 518F15 522C17 522K21 523A19 528H06 528P11 530H18 ... >> 585K18 >> >> $V3 >> [1] 518F15 >> 20 Levels: 518F15 522C17 522K21 523A19 528H06 528P11 530H18 534L09 ... >> 590C18 >> >> [[3]] >> [1] "505E01" >> >> and I haven't had any luck with variations on this that I've tried. >> >> >> Many thanks in advance for any help. >> >> ______________________________________________ >> 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.