[R] xlim/ylim and actual axis length

[Duncan Murdoch]

Peter Neuhaus wrote:
> Dear plotting wizards,
>
> when plotting in R, the actual lengths of the axes are slightly
> greater than the ranges of the x/y variables or xlim/ylim values.
>
> how do I control the amount by which the axes are enlarged? Is
> there a way to enforce that the lengths of the axes equal
> xlim/ylim?
>
> example:
>
> plot(0:100,0:100,pch="+")
>
> it can be observed, that the x- and y-axis join at approx. (-4,-4)
> and (104,104). If I want the axes to join at (0,0) and (100,100)
> I have to cheat R into doing it by providing wrong xlim/ylim values:
>
> plot(0:100,0:100,pch="+",xlim=c(4,96),ylim=c(4,96))
>
> is there a proper way to control this? I've been reading through
> the help for "par" but I still have no clue.
>   

If you use xaxs="i" in your call, the axes won't be extended.  If you 
want them extended by something other than the default amount, you 
should  probably use both xaxs="i" and xlim=... for fine control.

Duncan Murdoch