[R] automatically calling dev.off()

[axionator]

Yes, the user could add something. Here, In about 90% of the time, he
won't. So it would be nice to have a dev.off() as default (and some extra
handling if more plot commands will follow).

On Tue, Sep 1, 2015 at 4:04 PM, Duncan Murdoch <murdoch.duncan at gmail.com>
wrote:

> On 01/09/2015 7:34 AM, axionator wrote:
> > Hi,
> > is there a way to automatically call dev.off()?
> > I use options(device="myfunc") to automatically open a device to print
> to.
> > Afterwards, I would like to close it (so that the file is actually
> written).
> > I tried to do it via addTaskCallback, but unfortunately, I have to use
> > Rserve and (for any reason), the callback does not work (in the default R
> > console on win7 it works, however).
> >
> > So, the following runs in the R console (but not via Rserve):
> >
> > mypng <- function(filename = "test.png", ...)
> > {
> >     times <- function(total = 2, str = "Task") {
> >         ctr <- 0
> >         function(expr, value, ok, visible) {
> >             ctr <<- ctr + 1
> >             keep.me <- (ctr < total)
> >             if (ctr == total) {
> >                 cat("ENDPRINT")
> >                 dev.off()
> >             }
> >             keep.me
> >         }
> >     }
> >     png(filename, ...)
> >     n <- addTaskCallback(times(1))
> > }
> > options(device="mypng")
> > plot(rnorm(333))
> >
>
> It wouldn't make sense to call dev.off() after the plot() command,
> because the user might be planning to add something to it.  You need to
> tell R that you are done, and that's what dev.off() is for.
>
> You can call it automatically in a function by using
>
> on.exit(dev.off())
>
> and it should happen automatically at the end of an R session, but it
> *shouldn't* happen after every plotting call.
>
> Duncan Murdoch
>
>

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