Replace X-axis with own values
Not sure if it's what you mean, but you can do this:
plot(1:10, xaxt = "n", xlab='Some Letters')
axis(1, at=1:10, labels=letters[1:10])
which then gives you the graph:
You could set labels = FALSE
inside axis(...)
and then print the labels in a separate command using text(...)
. This option would allow you to rotate the text in case you need it.
lablist<-as.vector(c(1:10))
axis(1, at=seq(1, 10, by=1), labels = FALSE)
text(seq(1, 10, by=1), par("usr")[3] - 0.2, labels = lablist, srt = 45, pos = 1, xpd = TRUE)
Detailed explanation here