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

[Peter Cowan]

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?

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
>