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Legend problem when exporting a plot to PDF

4 messages · Julien Roux, Philipp Pagel, Brian Ripley +1 more

Original
Julien Roux
# 
Hi list,

When exporting to PDF a graph with a legend, in the final PDF, the text 
is going beyond the legend box.
 > dev2bitmap("test.pdf", type="pdfwrite", h=6, w=6)
The legend looks OK on the screen.
I noticed that the size of the legend box depends on the size of the 
screen window, which is not the case for other graphical parts (text of 
the legend, title, axis text...)
Any tip on how to deal with this?

Another problem I encounter, which may be linked to this is:
When I want to export PDFs to a given size with dev2bitmap (let's say 
h=3 and w=3), the size of the text of x-labels, y-labels and the x-axis 
annotations is not adjusted. The margins also keep the same size. Then 
if the size is too small, all the text fields overlap and the result is 
not nice.
How to change this? I guess it's possible since the on the screen (x11) 
the margins are adjusted relative to the size of the plot.

If you know one good tutorial to help creating ready-to-publish 
graphics, I would appreciate the reference.
Thanks for your help
Julien

PS:
R version 2.6.2 (2008-02-08)
i386-apple-darwin8.10.1
Philipp Pagel
# 
As far as I remember, te problem has to do with different font handling
in different devices. I'm sure someone more familiar wiht the internals
will comment on this.

The fix is easy: don't use dev2bitmap but open the desired target device
before plotting. In your case: 

pdf(file='test.pdf', width=6, height=6)
plot(...)
legend(...)
dev.off()

cu
	Philipp
Brian Ripley
# 
Copying between devices (as in dev2bitmap) is not a good way to produce 
high-quality graphs, and especially not if you change the size.

What is wrong with

pdf("test.pdf", width=6, height=6)
< re-run the plot commands>
dev.off()

?
On Tue, 29 Apr 2008, Julien Roux wrote:

            

      
      
      
    

        
With R version 2.7.0 you have other possibilities, including 
dev.copy2pdf() and quartz(type="pdf").

            

      
      
      
    

        

      
      
    

        

  
    

      
      
    

  


  


      

    

    

      
      

        


  

        

      Joerg van den Hoff
    

    

      
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On Tue, Apr 29, 2008 at 01:49:01PM +0200, Philipp Pagel wrote:

            

      
      
      
    

        
I'm not sure, whether this is the way to go. at least until recently the `pdf'
device of R had a few rough edges which surfaced by an then. In my experience
using `dev2bitmap(type="pdfwrite", ...)' -- and thus ghostscript for pdf
generation resulted in cleaner/better pdf output (actually, `dev2bitmap' sort
of postprocessess output from the `pdf' device a bit).

concerning the original question: yes, the problem is there. I believe it
is related simply to the fact that the same absolute font size used in the graphic window
is used in the pdf output, too, which makes its _relative_ size  dependent on the
chosen size (widht/height) of the pdf output. 

my workaround is to ensure that the graphic windows size is exactly the same
as that used in the `dev2bitmap` call. e.g. the X11() device has defaults of
width = 7, height = 7 (but you can enforce other values by open a new one with,
e.g., X11(width = 6, height = 9). thus, first plot to graphic window, make sure
that no interactive resizing is necessary to get acceptable display on the
monitor (otherwise close it and open new X11() with better width/height values). 
then call dev2bitmap() with the same width/height settings. that should lead essentially
to WYSIWYG (modulo font substitution, maybe).

joerg