convertRatings <- function (ratings) 
{
    lev <- levels(as.factor(ratings))
    ratings <- as.matrix(na.omit(ratings))
    ns <- nrow(ratings)
    target <- array(0, dim=c(ns,4))
    for (i in 1:ns) {
	if(ratings[i] == lev[1])
		target[i, 1] <- 1
	else if(ratings[i] == lev[2])
		target[i, 2] <- 1
	else if(ratings[i] == lev[3])
		target[i, 3] <- 1
	else if(ratings[i] == lev[4])
		target[i, 4] <- 1
    }
    return(target)
}

convertRatings3 <- function (ratings) 
{
    #ns is used just to iterate the for loop
    # and to define the number of columns in the target matrix
    ns <- nrow(ratings)

    # the resulting matrix
    target <- array(dim=c(2,ns))

    for (i in 1:ns){
       for (j in 1:4) {
	  if ((j == 1) && (ratings[i, j] == 1)){
		target[1,i] = ">"
		target[2,i] = "<"
		j = 5
	  }
	  else if ((j == 2) && (ratings[i, j] == 1)){
		target[1,i] = "<"
		target[2,i] = ">"
		j = 5
	  }
	  else if ((j == 3) && (ratings[i, j] == 1)){
		target[1,i] = "="
		target[2,i] = "="
		j = 5
	  }
       }
    }
    return(target)
}