Increasing barplot values in R

Question

I have managed to "declare" an empty barplot as shown below using the command:

barplot(c(0, 0, 0, 0, 0), names.arg = c("a", "b", "c", "d", "e"), ylim = c(0,1000)) 

How can I "add" values to any bars such that I can achieve something like this:

Answer 1

You can certainly do this, though it is not ideal:

dat <- rep(NA,5)
barplot(dat, names.arg = c("a", "b", "c", "d", "e"), ylim = c(0,1000)) 
barplot(replace(rep(NA,5),1,100), ylim = c(0,1000), yaxt="n", add=TRUE)
#                         ^---- position of new bar
#                             ^------value of new bar

This won't work perfectly, if for example you want to overwrite an old bar with a lower value, but it will be close enough.

Generally you'd be better off saving all the data and redrawing the entire plot each time.