Sorry that I did not make my question clear enough.
If the device is file based (e.g., a PNG file), then I believe I can do
that, by using functions that can inspect an image. This is the solution I
originally wanted to try. However, it requires creating a file in the
process.
I would like to see whether it is possible to inspect the canvas if the
device is an on-screen one, like the pop-up window in R for Windows.
Regards,
Shu Fai
On Sun, Oct 15, 2023 at 11:31?PM Jeff Newmiller <jdnewmil at
dcn.davis.ca.us>
wrote:
> This question is not clear to me. What is it you hope to retrieve from the
> device?
>
> Note that the type of device in your example is system-dependent. The
> content in a png() would be different than the content in a win.graph()
> device.
>
> On October 15, 2023 8:04:00 AM PDT, Shu Fai Cheung <
> shufai.cheung at gmail.com> wrote:
> >Hi All,
> >
> >I want to inspect the content of a plot generated by another function.
> >
> >For example:
> >
> >plot.new()
> >polygon(c(.5, .5, .75, .8), c(.25, .3, .4, .5))
> >
> >A polygon will be drawn. If I do not know what has been done to
generate
> >the plot, is it possible to query the content in the active device?
> >
> >Regards,
> >Shu Fai
> >
> > [[alternative HTML version deleted]]
> >
> >______________________________________________
> >R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
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> >PLEASE do read the posting guide
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> >and provide commented, minimal, self-contained, reproducible code.
>
> --
> Sent from my phone. Please excuse my brevity.
>
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