[R] Undesired tick marks on top, right axes

[Rich Shepard]

On Tue, 11 Sep 2018, Bert Gunter wrote:

> Well, you might try ?xyplot -- in particular the "scales" list section
> and in particular there the "tck" parameter. Adding
> tck = c(1, 0)
> to the "scales ="  list will probably solve your problem.

Bert,

   I missed the end of the tck description in the book (the same text as the
help file but with more information) where it mentions that tck can be a
vector of length 2 where the first element affects the left/bottom axes and
the second element affects the right/top axes. I also did not grok turning
the first element on and the second element off.

   Now I wonder why this wasn't an issue before now in the xyplots I created.

Thanks much,

Rich