R/pcdesign.R

In prefmod: Utilities to Fit Paired Comparison Models for Preferences

# PC design matrix    (12),(13),(23),(14),(24),...
pcdesign <- function(nobj)
{
  ncomp<-nobj*(nobj-1)/2          # number of comparisons
  obj<-matrix(0,ncomp,nobj)
  row<-1
     for (j in 2:nobj) {
         for (i in 1:(j-1) ){
             obj[row, i]  <-   1
             obj[row, j]  <-  -1
             row <- row + 1
         }
     }
  obj
}