R/alphabet-set.R

In TraMineR: Trajectory Miner: a Sequence Analysis Toolkit

## ====================================
## Function to set the alphabet
## of a sequence object
## ====================================

"alphabet<-" <- function(seqdata, value) {

  if (any(duplicated(value)))
		stop("[!] duplicated element(s) in value assigned to alphabet: ",value[duplicated(value)])

	if (!inherits(seqdata,"stslist"))
		stop("[!] data is not a sequence object, see seqdef function to create one")

	nbstate <- length(alphabet(seqdata))
	
	if (length(value)!=nbstate)
		stop("[!] number of states must be ",nbstate)
	else {
		for (i in 1:dim(seqdata)[2])
			levels(seqdata[,i])[1:nbstate] <- value

		if (isTRUE(all.equal(attr(seqdata,"alphabet"),attr(seqdata,"labels"))))
			attr(seqdata,"labels") <- value

		attr(seqdata,"alphabet") <- value
	}

	seqdata

}