[R-SIG-Mac] filled.contours and quartz() problem

[Marc Schwartz]

On Oct 30, 2009, at 11:53 AM, Joerg van den Hoff wrote:

> On Oct 30 2009 (Fri, 11:38), Simon Urbanek wrote:
>>
>> On Oct 30, 2009, at 11:05 , Joerg van den Hoff wrote:
>>
>>> has someone tried `filled.contours' with a `quartz' device?
>>>
>>> for me, contrary to using `X11' the display is corrupted by
>>> visible rendering of all contour lines (looks as if `contour'
>>> output is overlayed on the image with a thin line width in a
>>> whitish color) as well as the pixel boundaries .
>>>
>>> the same happens, when I first draw to `X11' and then
>>> `dev.print' to a pdf-file: with `gv' under X everything looks fine,
>>> using `PreView' under Aqua looks like the `quartz' ouput.
>>>
>>> I know that Apple's pdf rendering engine used to be buggy (don't  
>>> know
>>> if this is still true) but I'm not sure that this is the reason.
>>>
>>> it seems that somehow gaps of one screen-pixel are introduced  
>>> between
>>> the constant-color patches.
>>>
>>> is this known? can something be done about this?
>>>
>>
>> FAQ 12.10
>
> thanks, I had'nt noticed that (quick googling before pestering the
> mailing list did'nt show this :-))
>
> but this was not quite/exclusively my problem: 12.10 addresses only  
> `image' behaviour and
> states that this is taken care of in quartz. for image, I can confirm
> that this is true.  but not for `filled.contours': here `quartz'  
> excatly
> shows what I have described previously.
>
> but by using quartz(antialias=F) the problem indeed goes away.
>
> so, indeed your answer solved my problem (thanks again). two last
> remarks: should FAQ 12.10 not be augmented in order to state that  
> use of
> `filled.contour' with quartz requires to use quartz(antialias=F)?
> it would be even better, I believe, to add an updated FAQ 12.10 to the
> manpage of quartz (and maybe `pdf'), which after all is a more  
> obvious place to look for a
> solution than the FAQ (which e.g. escaped my attention altogether...)
>
>
> joerg


FWIW, this is also covered in the general R FAQ 7.36:

http://cran.r-project.org/doc/FAQ/R-FAQ.html#Why-are-there-unwanted-borders

HTH,

Marc Schwartz