[R] Transparent backgrounds in png files

[Patrick Connolly]

The result I'm aiming to achieve is a bitmap that can be imported into
a PowerPoint file that shows what's behind the lines of the plot.
There's a way in PowerPoint that almost works.  By choosing a colour
to set as transparent, what is behind the graphic is indeed visible,
but it's at the expense of losing line and text definition.

I notice there have been discussions about transparent backgrounds
mostly with lattice plots.  The problem most people seem to have was
getting a blue background when they wanted a white one.

Mine is the reverse (and I'm using standard graphics, not Lattice).
I'm trying to get a transparent background but it always comes out
white.  Setting bg = "transparent", I've tried using a bitmap device
to create a png file.  I've also tried creating a postscript file and
converting it to a PNG file using the Gimp.  I've always used a
resolution of 300 dpi in bitmaps since the default is far too low.

Other ideas appreciated.

> version
         _                
platform i686-pc-linux-gnu
arch     i686             
os       linux-gnu        
system   i686, linux-gnu  
status                    
major    1                
minor    9.1              
year     2004             
month    06               
day      21               
language R                



Thanks.

-- 
Patrick Connolly
HortResearch
Mt Albert
Auckland
New Zealand 
Ph: +64-9 815 4200 x 7188
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