I have a categorical variable with 3 levels: low, mid, and high. I want to do all-pair comparisons with the following contrasts:
lowVSmid = c(1,-1,0) lowVShigh = c(1,0,-1) midVShigh = c(0,1,-1) contrasts(df$var) = cbind(lowVSmid, lowVShigh,midVShigh)
However, when I print the contrast, I only see two:
contrasts(df$var) lowVSmid lowVShigh Low 1 1 Medium -1 0 High 0 -1
What am I doing wrong?