Alternate solution with the combinat package: m <- hcube(c(2, 2, 2)) m[m==1] <- -1 m[m==2] <- 1
Gabor On Mon, May 08, 2006 at 03:45:37PM -0600, Greg Snow wrote: > Try expand.grid: > > expand.grid( c(-1,1), c(-1,1), c(-1,1) ) > > > -- > Gregory (Greg) L. Snow Ph.D. > Statistical Data Center > Intermountain Healthcare > [EMAIL PROTECTED] > (801) 408-8111 > > > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Nameeta Lobo > Sent: Monday, May 08, 2006 3:33 PM > To: [email protected] > Subject: [R] Non repetitive permutations/combinations of elements > > > Hello all, > > I am trying to create a matrix of 1s and -1s without any repetitions for > a specified number of columns. > e.g. 1s and -1s for 3 columns can be done uniquely in 2^3 ways. > -1 -1 -1 > -1 -1 1 > -1 1 -1 > -1 1 1 > 1 -1 -1 > 1 -1 1 > 1 1 -1 > 1 1 1 > and for 4 columns in 2^4 ways and so on. > > I finally used the function combn([0 1],3) that I found at the following > link > http://www.mathworks.com/matlabcentral/fileexchange/loadFile.do?objectId > =7147&objectType=FILE > written by Jos van der Geest in Matlab which generated the above. > > > How can I do this is R? I have looked at permn and combn in the combinat > library and permutations and combinations in the gtools library and I am > still confused as to how to get it to work. > > Any suggestions will be truly appreciated. > > Thank you > > Nameeta > > > > ------------------------------------------------- > This email is intended only for the use of the individual\ o...{{dropped}} > > ______________________________________________ > [email protected] mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html -- Csardi Gabor <[EMAIL PROTECTED]> MTA RMKI, ELTE TTK ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
