[R] grid layout scaling viewport width based solely on height

[Peter Cowan]

Paul,

That is exactly what I was looking for.  Thank you!

Peter

On Sun, Aug 10, 2008 at 1:41 PM, Paul Murrell <p.murrell at auckland.ac.nz> wrote:
> Hi
>
>
> Peter Cowan wrote:
>> Paul,
>>
>> On Wed, Aug 6, 2008 at 1:40 PM, Paul Murrell <p.murrell at auckland.ac.nz> wrote:
>>>> I'm trying to write a function that produces a main plotting region
>>>> with several square plots along the right side.  Ideally the size of
>>>> right side plots will scale only with the height of the entire plot,
>>>> yet never overlap with another secondary plot.  The following two
>>>> snippets get close, however, as I resize the plot horizontally the
>>>> right side plots (green squares) get smaller whereas I'd like them to
>>>> remain the same size.  It seems the answer lies in setting the layout
>>>> width for the side plot column in a clever way that I haven't been
>>>> able to discover.  Any suggestions on how to achieve that effect or
>>>> other improvements to the below code are most welcome.
>>>>
>>>> Hopefully, my explanation makes my goal clear.  Also note, the real
>>>> application is a function that will have arbitrary numbers of side
>>>> plots.
>>
>>> Sorry, I'm not completely sure what you want to end up with, but do
>>> either of the following come close ?
>>
>> Thanks for the response.  Of the two suggestions the latter is close
>> to what I was hoping four.  However, ideally there would be no gap
>> between the side plots when the plot is 'tall'.  Phrased another way,
>> as the total plot gets larger, I would like the second column of the
>> lay1 to take up a greater proportion of the figure. So that a resize
>> in the Y, changes the allocation of column space in the X.  I don't
>> suppose that is possible, is it?
>
>
> It is, with a little more work ...
>
> # Side plots square and take up as much room as they are allowed
> # A special grob that is not drawn, but has the required height for the
> # side plots
> squareGrob <- grob(height=unit(.1, "npc"),
>                   cl="squareGrob")
> # A method for determining the width of the special grob based
> # on its height.
> # The important point is that this calculation will get redone
> # every time the squareGrob is asked for its width.
> widthDetails.squareGrob <- function(x) {
>      convertUnit(unit(.1, "npc"),
>                  "npc",
>                  "y", "dimension",
>                  "x", "dimension")
> }
> # A layout where the width of the second column is based
> # on the width of the special grob (first column width
> # takes up whatever width is left over)
> lay1 <- grid.layout(10, 2,
>                    widths=unit.c(unit(1, "null"),
>                                  grobWidth(squareGrob)),
>                    heights=unit(.1, "npc"))
>
> ... Once that squareGrob is defined, you can use it anywhere, so that's
> a one-off cost.  The following code shows the resulting layout ...
>
> # grid.newpage()
> pushViewport(viewport(layout=lay1))
>
> pushViewport(viewport(layout.pos.col=1))
> grid.rect(gp=gpar(fill="grey"))
> popViewport()
>
> for (i in 1:10) {
>    pushViewport(viewport(layout.pos.col=2,
>                          layout.pos.row=i))
>    grid.rect(gp=gpar(fill="light grey"))
>    popViewport()
> }
>
> ... does that do the job ?
>
> Paul
>
>
>> Cheers
>>
>> Peter
>>
>>> # Side plots square and attached to each other
>>> # With "tall" plot, get gaps top and bottom
>>> # With "wide" plot, get gap on the right
>>> lay1 <- grid.layout(1, 2, widths=c(10, 1))
>>> lay2 <- grid.layout(10, 1, respect=TRUE, just="left")
>>>
>>> # grid.newpage()
>>> pushViewport(viewport(width=.8, height=.8, layout=lay1))
>>> grid.rect(gp=gpar(col="grey"))
>>>
>>> pushViewport(viewport(layout.pos.col=1))
>>> grid.rect(gp=gpar(fill="grey"))
>>> popViewport()
>>>
>>> pushViewport(viewport(layout.pos.col=2,
>>>                      layout=lay2))
>>> for (i in 1:10) {
>>>    pushViewport(viewport(layout.pos.row=i))
>>>    grid.rect(gp=gpar(fill="light grey"))
>>>    popViewport()
>>> }
>>> popViewport()
>>>
>>>
>>> # Side plots square and separate from each other
>>> # With "tall" plot, get gaps between vertically
>>> # With "wide" plot, get gap on the right
>>> lay1 <- grid.layout(10, 2, widths=c(10, 1))
>>>
>>> # grid.newpage()
>>> pushViewport(viewport(width=.8, height=.8, layout=lay1))
>>> grid.rect(gp=gpar(col="grey"))
>>>
>>> pushViewport(viewport(layout.pos.col=1))
>>> grid.rect(gp=gpar(fill="grey"))
>>> popViewport()
>>>
>>> for (i in 1:10) {
>>>    pushViewport(viewport(layout.pos.col=2,
>>>                          layout.pos.row=i))
>>>    pushViewport(viewport(x=0, width=unit(1, "snpc"),
>>>                          height=unit(1, "snpc"), just="left"))
>>>    grid.rect(gp=gpar(fill="light grey"))
>>>    popViewport(2)
>>> }
>>>
>>> Paul
>>>
>
> --
> Dr Paul Murrell
> Department of Statistics
> The University of Auckland
> Private Bag 92019
> Auckland
> New Zealand
> 64 9 3737599 x85392
> paul at stat.auckland.ac.nz
> http://www.stat.auckland.ac.nz/~paul/
>