[R] par("plt") behaving inconsistely? bug?

[Murat Tasan]

Another (easier) kludge is augmenting a call to each par("plt" = ...) call:

par("plt" = some_plt_coordinates); box(lty = 0)

The box(lty = 0) addition makes downstream calls work as expected, but
yeah... this is a kuldge.

-m

On Mon, Oct 6, 2014 at 12:00 PM, Murat Tasan <mmuurr at gmail.com> wrote:
> Hi all -- I just encountered a behavior that I believe has changed
> from previous versions, though I haven't chased back the last version
> that behaves as my existing code expects quite yet.
> Perhaps this is a bug, though perhaps I'm missing a subtle detail
> somewhere in the documentation...
>
> Here's some code that works as expected (in R 3.1.1):
>
> ########################################
> pdf()
> plot.new()
>
> original_plt <- par("plt")
>
> plt_1 <- c(original_plt[1],
>            original_plt[1] + (original_plt[2] - original_plt[1]) / 2,
>            original_plt[3],
>            original_plt[3] + (original_plt[4] - original_plt[3]) / 2)
> par("plt" = plt_1)
> plot.window(xlim = c(0, 1), ylim = c(0, 1))
> box()
> plt_2 <- c(plt_1[2],
>            original_plt[2],
>            plt_1[4],
>            original_plt[4])
> par("plt" = plt_2)
> plot.window(xlim = c(0, 1), ylim = c(0, 1))
> box()
> par("plt" = original_plt)
> box(lty = 2)
> dev.off()
> ########################################
>
> This will draw 3 boxes... one in the lower left corner (specified by
> plt_1), one in the top right corner (specified by plt_2), and one
> dotted box around the full plot box (original_plt).
>
> Now, if you replace the first two box() calls by: rect(0, 0, 1, 1),
> only the lower-left rectangle is drawn.
> If you _add_ rect(0, 0, 1, 1) after each box() call, all boxes and
> rectangles are correctly drawn.
>
> It seems that after setting plt once, subsequent plt alterations put
> the device into a state that will permits drawing of _some_ things
> (e.g. box()), but not other things (e.g. rect, lines, points).
>
> A kludge to fix this is to call box(col = "white")... but that's quite
> the kludge, indeed!
> Axis() works just like box(), too... but I haven't exhausted which
> drawing functions work and which don't.
>
> I'd classify this is a bug, but I thought I'd check here first.
> I've also only checked this so far with the pdf() device, so I don't
> know if it is somehow device-specific.
>
> I detected this because some existing code (that worked on some
> earlier version of R, sorry that I don't know which one yet...) has
> suddenly stopped working!
>
> Cheers!
>
> -murat