[Rd] invalid graphics state using dev.print (fwd)

[Hin-Tak Leung]

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