Multi-density plot

Functionality

Plotting multiple density lines for a value which can be subdivided into categories:

Code:

multidensity<-function(dat,idx_col,val_name,fill=T,boarder=F,col_func=rainbow,legend_loc="topleft",from=NULL,to=NULL,...){
    library(scales)
    val_col<-match(val_name,colnames(dat))
    lvls<-sort(unique(dat[,idx_col]))
    num_levels<-length(lvls)    
    cols<- col_func(num_levels)
    trans_cols<-alpha(cols,0.3)
    ymax<-max(sapply(lvls,function(lvl){max(density(dat[dat[,idx_col]==lvl,val_col],from=0,to=1)$y)}))
    if (is.null(from)){from<-min(dat[,val_col])}
    if (is.null(to)){to<-max(dat[,val_col])}
    if (!("xlim" %in% names(list(...)))){
        plot(0,0,type="n",ylim=c(0,ymax),xlim=c(from,to),...)

    } else {
        plot(0,0,type="n",ylim=c(0,ymax),...)        
    }
    for (lvl in lvls){
        d<-density(dat[dat[,idx_col]==lvl,val_col],from=from,to=to)
        if (fill==T){    polygon(c(min(d$x),d$x,max(d$x)),c(0,d$y,0),col=trans_cols[match(lvl,lvls)])}
        if (boarder==T){    lines(c(d$x,1),c(d$y,0),col=cols[match(lvl,lvls)])}
    }
    legend(legend_loc,legend=lvls,fill=cols)
}

Usage:

multidensity(x,idx_col,val_name)

Arguments: