How to add color on plot using factor variable as one of the axis?

Question

I just would like to add color on a plot but it seems that the classic col function does not work when a factor variable is used as one of the axis. Here is an example of what I do:

df<-data.frame(x=runif(1000,1,1000))

df$class<-Hmisc::cut2(df$x, g=10)

df.agg<-aggregate(df$x, by=list(df$class), FUN=sum)

plot(df.agg$Group.1, df.agg$x, col="red")

The plot values appear black. How to add color on this type of graph ?

Answer 1

In this case you are actually making a boxplot because x is factor and y is numeric. For boxplot line colors are controled with argumnt border=

plot(df.agg$Group.1, df.agg$x, border="red")

You can see it by making the same plot with function boxplot().

boxplot(df.agg$x~df.agg$Group.1, , border="red")