R/makeNominalData.R

In ExPosition: Exploratory Analysis with the Singular Value Decomposition

makeNominalData <-
function(datain){
    num.nas <- sum(is.na(datain))
    if (num.nas > 0) {
        print(paste("You have ", num.nas, " NAs in your data. makeNominalData automatically imputes NA with the mean of the columns.", 
            sep = ""))
    }
    data_dims <- dim(datain)
    var_names <- colnames(datain)
    ind_names <- rownames(datain)
    new_column_count <- 0
    for (i in 1:data_dims[2]) {
        unique_elements <- unique(datain[, i])
        new_column_count <- new_column_count + length(unique_elements[!is.na(unique_elements)])
    }
    dataout <- matrix(0, data_dims[1], new_column_count)
    beginner <- 0
    new_colnames <- matrix(0, 1, 0)
    for (i in 1:data_dims[2]) {
        unique_elements <- unique(datain[, i])
        unique_no_na <- unique_elements[!is.na(unique_elements)]
        mini.mat <- matrix(0, data_dims[1], length(unique_no_na))
        for (j in 1:ncol(mini.mat)) {
            mini.mat[which(datain[, i] == unique_no_na[j]), j] <- 1
            new_colnames <- cbind(new_colnames, paste(var_names[i], 
                ".", unique_no_na[j], sep = ""))
        }
        
        if(length(which(rowSums(mini.mat) == 0)) > 0){
	        barycenter <- colSums(mini.mat)/sum(colSums(mini.mat))
        
        	fill_in <- matrix(barycenter,
        					length(which(rowSums(mini.mat) == 0)),
            				length(barycenter),
            				byrow=TRUE)	
        	mini.mat[which(rowSums(mini.mat) == 0), ] <- fill_in
        }
        
        ender <- beginner + length(unique_no_na)
        dataout[, (beginner + 1):ender] <- mini.mat
        beginner <- ender
    }
    colnames(dataout) <- new_colnames
    rownames(dataout) <- ind_names
    return(as.matrix(dataout))
}