R devel - Sep 2013 - recordPlot() on non-interactive graphics device?

Hi.

Q. Is there a way to record a plot using grDevices::recordPlot()
without opening an interactive (=visible GUI window) graphics device
(not even for a flash of a second)?


Related: help("recordPlot", package="grDevices") says:

"These functions record and replay the displaylist of the current
graphics device."

Is the intention that recordPlot() should be able to record from _any
type_ of graphics device, or only for _interactive_ ones?   For
instance,

windows(); plot(1:10); g <- recordPlot(); dev.off();
x11(); plot(1:10); g <- recordPlot(); dev.off();
Cairo::CairoWin(); plot(1:10); g <- recordPlot(); dev.off();

all produce 'recordplot' objects that replot the figure with
replayPlot(g), whereas for instance

png("foo.png"); plot(1:10); g <- recordPlot(); dev.off();
pdf("foo.pdf"); plot(1:10); g <- recordPlot(); dev.off();

produce "empty" replayPlot(g) outputs.

Q. It it just a coincident that it appear that
recordPlot()/replayPlot() only works for
grDevices::deviceIsInteractive() graphics devices?  If not, should
?recordPlot clarify that "These functions record and replay the
displaylist of the current [interactive] graphics device."?

Q. ...or is just the fact that currently png(), pdf() etc. won't
populate "the displaylist" (whatever that is), but if they would, then
recordPlot()/replayPlot() would indeed generate an non-empty plot?  If
so, a note like "Note, recordPlot() will often record an empty plot on
non-interactive graphics devices as they do not populate the
displaylist." may be add to the help.


Thanks,

Henrik

Henrik,

This works for me:
> png("test.png")
> dev.control(displaylist="enable")
> plot(1:10)
> rp = recordPlot()
> dev.off()
X11cairo
       2
> rp
HTH,
~G

sessionInfo():
R version 3.0.1 (2013-05-16)
Platform: x86_64-pc-linux-gnu (64-bit)

locale:
 [1] LC_CTYPE=en_US.UTF-8       LC_NUMERIC=C
 [3] LC_TIME=en_US.UTF-8        LC_COLLATE=en_US.UTF-8
 [5] LC_MONETARY=en_US.UTF-8    LC_MESSAGES=en_US.UTF-8
 [7] LC_PAPER=C                 LC_NAME=C
 [9] LC_ADDRESS=C               LC_TELEPHONE=C
[11] LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base

loaded via a namespace (and not attached):
[1] tools_3.0.1



On Tue, Sep 24, 2013 at 11:14 AM, Henrik Bengtsson
<hb@biostat.ucsf.edu>wrote:
> Hi.
>
> Q. Is there a way to record a plot using grDevices::recordPlot()
> without opening an interactive (=visible GUI window) graphics device
> (not even for a flash of a second)?
>
>
> Related: help("recordPlot", package="grDevices") says:
>
> "These functions record and replay the displaylist of the current
> graphics device."
>
> Is the intention that recordPlot() should be able to record from _any
> type_ of graphics device, or only for _interactive_ ones?   For
> instance,
>
> windows(); plot(1:10); g <- recordPlot(); dev.off();
> x11(); plot(1:10); g <- recordPlot(); dev.off();
> Cairo::CairoWin(); plot(1:10); g <- recordPlot(); dev.off();
>
> all produce 'recordplot' objects that replot the figure with
> replayPlot(g), whereas for instance
>
> png("foo.png"); plot(1:10); g <- recordPlot(); dev.off();
> pdf("foo.pdf"); plot(1:10); g <- recordPlot(); dev.off();
>
> produce "empty" replayPlot(g) outputs.
>
> Q. It it just a coincident that it appear that
> recordPlot()/replayPlot() only works for
> grDevices::deviceIsInteractive() graphics devices?  If not, should
> ?recordPlot clarify that "These functions record and replay the
> displaylist of the current [interactive] graphics device."?
>
> Q. ...or is just the fact that currently png(), pdf() etc. won't
> populate "the displaylist" (whatever that is), but if they would,
then
> recordPlot()/replayPlot() would indeed generate an non-empty plot?  If
> so, a note like "Note, recordPlot() will often record an empty plot on
> non-interactive graphics devices as they do not populate the
> displaylist." may be add to the help.
>
>
> Thanks,
>
> Henrik
>
> ______________________________________________
> R-devel@r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel
>


-- 
Gabriel Becker
Graduate Student
Statistics Department
University of California, Davis

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