[R] Coordinates of the current plot

[petr at orbit.umbr.cas.cz]

Hi,
Is is possible to obtain/ get coordinates of the current graphics? I am using
plot function for hclust object and I want to add some additional graphics
but I cannot figure out what  ylim and xlim is used for actual ploting of
tree. I know that I can probably used ploting of dendrogram instead but I
need to use hclust class since it better manage the huge amount data I
p[lotting. thanks for help
Petr Novak