search for: imiat

...he basal category of x3, (coincident with the corresponding result of summary(reg3)), so that it is not what I am looking for, and it seems that when I write (contrasts=c("contr.sum", "contr.poly")) before fit.contrast, it adjust for x3. Here I send a SMALL EXAMPLE that tries to imiate my problem. library(gmodels) set.seed(100) options(contrasts=c("contr.treatment", "contr.poly")) y <- rnorm(100) x <- cut(rnorm(100, mean=y, sd=0.25),c(-4,-1.5,0,1.5,4)) # 4 CATEGORIES x3 <- cut(rnorm(100, mean=y, sd=8),c(-50,0,50)) # 2 CATEGORIES reg3<-lm(y~ x...