[R] plot custom x axis ticks values

[e-letter]

On 14/02/2013, PIKAL Petr <petr.pikal at precheza.cz> wrote:
> Hi
>
> much quicker and better for you is to inspect help pages.
>
> ?axis
>
> axis(1, at=1:4, labels=c(letters[1:4]))

Had tried, but noticed that the labels created were not positioned
equally across the entire axis, but occupied about 50 % (the left
half) of the axis. How to change this please?