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

[Murat Tasan]

6. iteratively downgrade to earlier versions of R until it's working
again... then try to diff out the offending source code change.
i can try this, but i probably won't get to it for at least a few weeks :-/

in the meantime, i'm tacking on box(lty = 0) to every par(plt = ...) call, e.g.
> par("plt" = some_plt_coordinates); box(lty = 0)

in the short term, this works.
clip(...), a combination of par("new" = TRUE); plot.new(), and a whole
bunch of other kludges work, too... pick your poison :-)

cheers and thanks!

-murat

On Mon, Oct 6, 2014 at 2:08 PM, Greg Snow <538280 at gmail.com> wrote:
> I believe that what is happening is that the clipping region is being
> reset when you call box, but not when you call rect.  If you insert
> the command "par(xpd=NA)" (or TRUE instead of NA) after the plot.new
> and use the rect commands then you can see both rectangles (because
> this turns the clipping off).  Working with the clipping region
> (indirectly in your case) is complex since some functions properly
> reset the region and others do not (and  making the others
> automatically reset it may cause other problems when they reset a
> clipping region that should not be reset).
>
> So the options are:
>
> 1 dive into the source code enough to figure out if fixing rect to
> work with the clipping region is simple or not and submitting a patch
> 2 wait for Prof Brian Ripley to notice this fact and do the above (he
> has fixed a couple of other functions when made aware)
> 3 use par(xpd=TRUE) (or NA) to not clip to the plotting region (this
> is simple, but will allow things to be drawn outside of the plotting
> region, on simple example is using abline)
> 4 use a function that properly sets the clipping region (such as box)
> before plotting anything else
> 5 call clip(0,1,0,1) (or with the actual user coordinates) to manually
> set the clipping region
> 6 other?
>
>
> 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
>>
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>
>
>
> --
> Gregory (Greg) L. Snow Ph.D.
> 538280 at gmail.com