[R] package grid: mirror grob objects along an axis

[baptiste auguie]

You can rotate the viewport to flip around the horizontal axis,

library(grid)
grid.text("Chiral")
grid.text("Chiral", vp=viewport(angle=180, y=unit(0.5,"npc")-unit(1,"line")))

HTH,

b.

On 23 May 2012 05:34, Thomas Zumbrunn <t.zumbrunn at unibas.ch> wrote:
> Maybe my question was not concise enough. I was referring to objects created
> with the "package "grid" (also called "grobs"), not to the function "grid"
> from package "graphics". For instance, let's say I have a polygon createad
> with grid::polygonGrob and want to mirror it along a specified axis. Of course
> one could transform the polygon's coordinates, but I was hoping that there is
> some more generic way of doing this (and that this could e.g. also be done
> with text grobs).
>
> Cheers
> /thomas
>
>
>
> On Tuesday 22 May 2012, Rui Barradas wrote:
>> Hello,
>>
>> Just flip 'xlim' or 'ylim'. Or both.
>> Using the iris example in help("grid"), make the following changes:
>>
>>
>> op <- par(mfcol = c(2,2))  # Two columns, first is the original, second
>> flipped.
>>
>> with(iris,
>>
>>       [... etc ...]
>>      # row 1, col 2: flip x axis
>>      plot(Sepal.Length, Sepal.Width, col = as.integer(Species),
>>           xlim = c(8, 4), ylim = c(2, 4.5), panel.first = grid(),
>>           main = "with(iris,  plot(...., panel.first = grid(), ..) )")
>>      # row 2, col 2: flip y axis
>>      plot(Sepal.Length, Sepal.Width, col = as.integer(Species),
>>           xlim = c(4, 8), ylim = c(4.5, 2),
>>           panel.first = grid(3, lty=1,lwd=2),
>>           main = "... panel.first = grid(3, lty=1,lwd=2), ..")
>>
>>      [... etc ...]
>> )
>> par(op)
>>
>>
>> Hope this helps,
>>
>> Rui Barradas
>>
>> Thomas Zumbrunn-3 wrote
>>
>> > Hi everyone
>> >
>> > I'd like to flip grobs (grid graphical objects) along an axis, e.g. flip
>> > grobs
>> > horizontally or vertically. I couldn't find any hints, neither in the
>> > documentation nor by searching the web. Does anybody know how to achieve
>> > this?
>> >
>> > Cheers
>> > /thomas
>> >
>> > ______________________________________________
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>> > PLEASE do read the posting guide
>> > http://www.R-project.org/posting-guide.html
>> > and provide commented, minimal, self-contained, reproducible code.
>>
>> --
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>> Nabble.com.
>>
>> ______________________________________________
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>> PLEASE do read the posting guide
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>
>
> --
> Thomas Zumbrunn, PhD
> Clinical Trial Unit (CTU)
> Universitätsspital Basel
> Schanzenstr. 55, CH-4031 Basel
> Tel +41 (0)61 556 52 92
> Fax +41 (0)61 265 94 10
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>
> ______________________________________________
> R-help at r-project.org mailing list
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> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.