Re: [R] Plotting directly to memory?

2023-05-28 Thread Jan van der Laan 



Perhaps the ragg package? That has an `agg_capture` device "that lets 
you access the device buffer directly from your R session." 
https://github.com/r-lib/ragg


HTH,
Jan




On 28-05-2023 13:46, Duncan Murdoch wrote:
Is there a way to open a graphics device that plots entirely to an array 
or raster in memory?  I'd prefer it to use base graphics, but grid would 
be fine if it makes a difference.


For an explicit example, I'd like to do the equivalent of this:

   filename <- tempfile(fileext = ".png")
   png(filename)
   plot(1:10, 1:10)
   dev.off()

   library(png)
   img <- readPNG(filename)

   unlink(filename)


which puts the desired plot into the array `img`, but I'd like to do it 
without needing the `png` package or the temporary file.


A possibly slightly simpler request would be to do this only for 
plotting text, i.e. I'd like to rasterize some text into an array.


Duncan Murdoch

__
R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide 
http://www.R-project.org/posting-guide.html

and provide commented, minimal, self-contained, reproducible code.


__
R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.

Re: [R] Plotting directly to memory?

2023-05-28 Thread Jeroen Ooms 
On Sun, May 28, 2023 at 1:46 PM Duncan Murdoch  wrote:
>
> Is there a way to open a graphics device that plots entirely to an array
> or raster in memory?  I'd prefer it to use base graphics, but grid would
> be fine if it makes a difference.
>
> For an explicit example, I'd like to do the equivalent of this:
>
>filename <- tempfile(fileext = ".png")
>png(filename)
>plot(1:10, 1:10)
>dev.off()
>
>library(png)
>img <- readPNG(filename)
>
>unlink(filename)
>

The magick package has this capability too:

library(magick)
img <- magick::image_device()
plot(1:10, 1:10)
dev.off()
image_data(img)

__
R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.