[r] How to specify the actual x axis values to plot as x axis ticks in R

I am creating a plot in R and I dont like the x axis values being plotted by R.

For example:

x <- seq(10,200,10)
y <- runif(x)

plot(x,y)

This plots a graph with the following values on the X axis:

50, 100, 150, 200

However, I want to plot the 20 values 10,20, 30 ... 200 stored in variable x, as the X axis values. I have scoured through countless blogs and the terse manual - after hours of searching, the closest I've come to finding anything useful is the following (summarized) instructions:

1. call plot() or par(), specifying argument xaxt='n'
2. call axis() e.g. axis(side = 1, at = seq(0, 10, by = 0.1), labels = FALSE, tcl = -0.2)

I tried it and the resulting plot had no x axis values at all. Is it possible that someone out there knows how to do this? I can't believe that no one has ever tried to do this before.

Take a closer look at the ?axis documentation. If you look at the description of the labels argument, you'll see that it is:

"a logical value specifying whether (numerical) annotations are 
to be made at the tickmarks,"

So, just change it to true, and you'll get your tick labels.

x <- seq(10,200,10)
y <- runif(x)
plot(x,y,xaxt='n')
axis(side = 1, at = x,labels = T)
# Since TRUE is the default for labels, you can just use axis(side=1,at=x)

Be careful that if you don't stretch your window width, then R might not be able to write all your labels in. Play with the window width and you'll see what I mean.

It's too bad that you had such trouble finding documentation! What were your search terms? Try typing r axis into Google, and the first link you will get is that Quick R page that I mentioned earlier. Scroll down to "Axes", and you'll get a very nice little guide on how to do it. You should probably check there first for any plotting questions, it will be faster than waiting for a SO reply.

Hope this coding will helps you :)

plot(x,y,xaxt = 'n')

axis(side=1,at=c(1,20,30,50),labels=c("1975","1980","1985","1990"))

In case of plotting time series, the command ts.plot requires a different argument than xaxt="n"

require(graphics)
ts.plot(ldeaths, mdeaths, xlab="year", ylab="deaths", lty=c(1:2), gpars=list(xaxt="n"))
axis(1, at = seq(1974, 1980, by = 2))