Wow! On Mon, Jul 27, 2015 at 5:28 PM, Bert Gunter <bgunter.4...@gmail.com> wrote: > ## I leave it to you to add the NA edges > >> rk <- c(2,4,3,1) > >> outer(rk,rk,"<")+0 > > [,1] [,2] [,3] [,4] > [1,] 0 1 1 0 > [2,] 0 0 0 0 > [3,] 0 1 0 0 > [4,] 1 1 1 0 > > > > Cheers, > Bert > > Bert Gunter > > "Data is not information. Information is not knowledge. And knowledge > is certainly not wisdom." > -- Clifford Stoll > > > On Mon, Jul 27, 2015 at 12:38 PM, Dimitri Liakhovitski > <dimitri.liakhovit...@gmail.com> wrote: >> I have 5 items in total (1:5), but I show a person only 4 items (1:4) >> and ask this person to rank items 1:4 in terms of preferences (1 is >> best, 2 is second best, 4 is worst), and I get a vector of ranks: >> ranks <- c(2,4,3,1) >> >> # That means that this person liked item 4 best and item 2 worst. >> >> I would like to "unfirl" this vector of ranks into a matrix of >> preferences where if the row item prefers the column item, then it's a >> 1. Otherwise, it's a zero. So, the output should be a 5 by 5 matrix >> (because overall we have 5 items, not 4, but item 5 did not >> participate in rankings), and it would always have zeros in a >> diagonal.: >> >> 0 1 1 0 NA >> 0 0 0 0 NA >> 0 1 0 0 NA >> 1 1 1 0 NA >> NA NA NA NA 0 >> >> I can loop through all possible pairs the person saw and fill the >> matrix accordingly, but it seems like a lot of looping. Could one do >> it in a more elegant way? >> >> Thank you very much! >> >> >> -- >> Dimitri Liakhovitski >> >> ______________________________________________ >> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see >> 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.
-- Dimitri Liakhovitski ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.
