I'd like to plot a scatter plot of X versus Y, but X is now of type character.
x = c("a", "b", "b", "c", "a")
y = c(9,2,4,5,1)
This should do the job
plot(y, xaxt="n") axis(1, at=1:length(x), labels=x)
Essentially you plot y hiding the x axis, then add a custom x axis to the plot.
?axis for more info.