[R] Source code for R graphics devices

[Duncan Murdoch]

On 7/10/2006 3:52 PM, (Ted Harding) wrote:
> Hi Folks,
> 
> I'm trying to locate the source code for a (typical)
> R graphics device, in order to study how it's done.
> 
> The underlying reason is that I'm thinking of trying
> to create a graphics device for 'pic' (the diagram
> drawing component of [g]troff).
> 
> I thought the xfig device would be a good place to
> look, since the format of an xfig file is similar in
> nature (though very different in detail) to 'pic' code.
> 
> When, in R, I type "xfig" to see the R code, I get the
> line
> 
>   .Internal(XFig(file, old$paper, old$family, old$bg, old$fg,
>       old$width, old$height, old$horizontal, old$pointsize, 
>       old$onefile, old$pagecentre))
> 
> so I tried to locate the code for the Internal function "Xfig".
> 
> I can't seem to find it!
> 
> So where should I be looking?

The devices are in the grDevices package.  Look in the src directory 
there for the C code.  XFig is in the devPS.c file.

Duncan Murdoch

> 
> Also -- a more general question on this topic -- presumably
> any R graphics device is driven by a "stream" of raw graphics
> data in some presumably device-independent format, which it
> then translates. Where can I find this, and information on
> its structure?
> 
> With thanks, and best wishes,
> Ted.
> 
> PS Total newbie on this front!

Then it might be worth mentioning that this code isn't distributed with 
a binary version of R, you need a source tarball, and need to look in 
src/library/grDevices/src.

Duncan Murdoch
> 
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> Date: 10-Jul-06                                       Time: 20:52:46
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