axis(which, at, labels=true, ...)
which
| an integer specifying which side of the plot the axis is to be drawn on. |
at
| the points at which tick-marks are to be drawn. |
labels
| this can either be a logical value specifying whether (numerical) annotations are to be made at the tickmarks, or a vector of character strings to be placed at the tickpoints. |
...
| graphical parameters can also be specified as parameters. |
axis adds an axis to an already existing plot.
The axis is placed as follows:
1=below, 2=left, 3=above and 4=right.
Examples
plot(1:4, rnorm(4), axes=false)
axis(1, 1:4, c("A", "B", "C", "D"))
axis(2)