factorDesign is not working

[onahman]

easy way to reproduce the bug:
toy_df = data.frame(x=c(1,2,3,4,5),y=as.factor(c(0,0,1,2,0)), z=c(10.23,19,20.42,12,1.221), w = as.factor(c(0,0,1,1,0)))
factorDesign(toy_df)

The resulting error:
Error in colnames<-(*tmp*, value = *vtmp*) : attempt to set 'colnames' on an object with less than two dimensions

I suggest the following corrections. it seem to work now:
factor.inds <- sapply(df[1, ], is.factor)
factor.labels <- which(factor.inds)
nfacs <- sum(factor.inds)
nlevs <- sapply(df[1, factor.inds], function(fac) nlevels(fac))
totnlevs <- sum(nlevs)
num.num = indcounter = ncol(df) - nfacs
x <- matrix(nrow = nrow(df), ncol = totnlevs + num.num)
colnames(x) <- 1:ncol(x)
index <- integer(ncol(x))
varnames <- character(ncol(df))
if (num.num > 0) {
x[, 1:num.num] <- as.matrix(df[, !factor.inds])
varnames[1:num.num] = colnames(x)[1:num.num] <- colnames(df)[!factor.inds]
index[1:num.num] <- 1:num.num
#indcounter <- indcounter + num.num - 1
}
for (j in 1:nfacs) {
submat <- model.matrix(~df[, factor.labels[j]] - 1)
indcounter <- indcounter + 1
submatinds <- indcounter:(indcounter + nlevs[j] - 1)
indcounter <- indcounter + nlevs[j] - 1
colnames(x)[submatinds] <- paste0(colnames(df)[factor.labels[j]], ":", 1:nlevs[j])
varnames[num.num + j] <- colnames(df)[factor.labels[j]]
x[, submatinds] <- submat
index[submatinds] <- num.num + j
}
attr(x, "varnames") <- varnames

[DanielEWeeks]

Yes, we encountered the same bug. Here's a minimal working example:

> a <- warpbreaks
> a <- cbind(warpbreaks$breaks, a)
> factorDesign(a)
Error in `colnames<-`(`*tmp*`, value = `*vtmp*`) : 
  attempt to set 'colnames' on an object with less than two dimensions