From hin-tak.leung at cimr.cam.ac.uk  Tue Feb 21 15:51:06 2006
From: hin-tak.leung at cimr.cam.ac.uk (Hin-Tak Leung)
Date: Tue, 21 Feb 2006 14:51:06 +0000
Subject: [Rd] invalid graphics state using dev.print (fwd)
In-Reply-To: <Pine.LNX.4.64.0602200833030.4588@gannet.stats.ox.ac.uk>
References: <Pine.OSF.4.58.0602081515590.512812@wotan.mdacc.tmc.edu>	<17388.51930.273876.336070@stat.math.ethz.ch>	<43F92420.4070706@stat.auckland.ac.nz>	<Pine.LNX.4.64.0602200714030.3798@gannet.stats.ox.ac.uk>
	<Pine.LNX.4.64.0602200833030.4588@gannet.stats.ox.ac.uk>
Message-ID: <43FB28DA.4080708@cimr.cam.ac.uk>

Prof Brian Ripley wrote:
> On Mon, 20 Feb 2006, Prof Brian Ripley wrote:
> 
>>On Mon, 20 Feb 2006, Paul Murrell wrote:
<snipped>
>>>>  >> x11()
>>>>  >> plot(rnorm(10))
>>>>  >> dev.print(png)
<snipped>
>>I don't think there is a way to do that unambiguously (there is no
>>standard way to do the conversion), and in any case dev.print() was passed
>>a function, not the name of a function, and so does not in general know
>>how it behaves (and your 'png' need not be R's png()).

There is a "standard" way of querying the X display directly about
the size each pixel supposedly represents - well, an X display can
be configured wrongly, etc, but you get what you ask for...

$ xdpyinfo |grep 'resolution'
   resolution:    75x75 dots per inch

(this 75x75 seems to be a default value as I did not set it anywhere,
but I believe it is configurable)

I am not sure about png files, but tiff files also have internal data
claiming x pixels corresponds to y inches. (and I am fairly sure jpeg
does *not* have this feature).

HTL



[Rd] invalid graphics state using dev.print (fwd)
Hin-Tak Leung