[Bioc-devel] PNG Graphics overwrite problem on MacOSX

Steffen Neumann sneumann at ipb-halle.de
Mon Jan 11 15:56:55 CET 2010

On Mon, 2010-01-11 at 07:59 -0500, Kasper Daniel Hansen wrote:
> Is this only for PNG are does this also seems weird when you use, say, pdf() on OS X?
I don't have a Mac at hand, so I can't test :-(

> It is hard to say, but it seems that the title is not just
> overplotting, but two different texts overplotted.
Yes, they have different texts, and the whole plots should've gone 
into different "%003d.png" files.

>   Are you explicitly drawing the title several times and for the other
> platforms the text just gets positioned exactly on top of each other,
> or are you sure you are only drawing the text once (this is impossible
> to tell from your snippet)?  
Plotting code is identical for all platforms. The full snippet is at
You see that I (or rather the original author :-) "uses" 
an plot(0, 0, type = "n", main = "Extracted ...", xlim=...)
to setup the plot including axes and title. My guess was that 
axes and main was not cleared between two consecutive "%003d.png",
which might explain the platform dependency.

Should I put in an explicit plot.new() ? 
I'd though that was done implicitely by plot() ?


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