R devel - Mar 2016 - Could unit.list() from grid package be made an exported function?

Hello,

certain manipulations of ggplot2 graphs, in particular aligning them, require
the function grid:::unit.list(). See e.g. these posts on stackoverflow:
http://stackoverflow.com/questions/34032621/element-replacement-in-grid-unit-vector
http://stackoverflow.com/questions/32580946/setting-absolute-size-of-facets-in-ggplot2/32583612#32583612
http://stackoverflow.com/a/35823179/4975218

Since this seems to be a reasonably common issue, would it be possible to export
grid:::unit.list(), so it can be used in packages?

(Am I sending this to the right audience? It?s not clear to me how to reach the
maintainer of the grid package in base R.)

Thanks!

Claus

--
Claus Wilke
Professor and Department Chair, Integrative Biology
The University of Texas at Austin
2500 Speedway, A4800
Austin, Texas 78712
512 232 2459


	[[alternative HTML version deleted]]

Hi

I think the right solution is to add [<- methods for units.
I will take a look at whether I can get that done for the release of R 3.3.0

Paul

On 07/03/16 07:34, Wilke, Claus O wrote:
> Hello,
>
> certain manipulations of ggplot2 graphs, in particular aligning them,
> require the function grid:::unit.list(). See e.g. these posts on
> stackoverflow:
>
http://stackoverflow.com/questions/34032621/element-replacement-in-grid-unit-vector
>
>
http://stackoverflow.com/questions/32580946/setting-absolute-size-of-facets-in-ggplot2/32583612#32583612
> http://stackoverflow.com/a/35823179/4975218
>
> Since this seems to be a reasonably common issue, would it be
> possible to export grid:::unit.list(), so it can be used in
> packages?
>
> (Am I sending this to the right audience? It?s not clear to me how to
> reach the maintainer of the grid package in base R.)
>
> Thanks!
>
> Claus
>
> -- Claus Wilke Professor and Department Chair, Integrative Biology
> The University of Texas at Austin 2500 Speedway, A4800 Austin, Texas
> 78712 512 232 2459
>
>
> [[alternative HTML version deleted]]
>
> ______________________________________________ R-devel at r-project.org
> mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
>
-- 
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/

Hi

Subassignment for units has been committed to r-devel.
You should now be able to do things like ...

x <- unit(1:3, "mm")
x[2] <- unit(.5, "npc")

(see grid/tests/units.R for more complex examples)

This works for me for the three stackoverflow scenarios.
Any confirmation that it also works for you would be welcome.

Paul

On 07/03/16 07:34, Wilke, Claus O wrote:
> Hello,
>
> certain manipulations of ggplot2 graphs, in particular aligning them,
> require the function grid:::unit.list(). See e.g. these posts on
> stackoverflow:
>
http://stackoverflow.com/questions/34032621/element-replacement-in-grid-unit-vector
>
>
http://stackoverflow.com/questions/32580946/setting-absolute-size-of-facets-in-ggplot2/32583612#32583612
> http://stackoverflow.com/a/35823179/4975218
>
> Since this seems to be a reasonably common issue, would it be
> possible to export grid:::unit.list(), so it can be used in
> packages?
>
> (Am I sending this to the right audience? It?s not clear to me how to
> reach the maintainer of the grid package in base R.)
>
> Thanks!
>
> Claus
>
> -- Claus Wilke Professor and Department Chair, Integrative Biology
> The University of Texas at Austin 2500 Speedway, A4800 Austin, Texas
> 78712 512 232 2459
>
>
> [[alternative HTML version deleted]]
>
> ______________________________________________ R-devel at r-project.org
> mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
>
-- 
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/

Paul,

Subassignment for units has been committed to r-devel.
You should now be able to do things like ...

x <- unit(1:3, "mm")
x[2] <- unit(.5, "npc")

(see grid/tests/units.R for more complex examples)

Yes, I just tried the latest R devel and it works for me. However:

This works for me for the three stackoverflow scenarios.

I ran into an additional problem when trying to replicate this example:
http://stackoverflow.com/a/32583612/4975218

This line in the function set_panel_size() causes an error for me:
g$widths[panel_index_w] <-  rep(list(width), nw)

Error in `[<-.unit`(`*tmp*`, panel_index_w, value = list(4, 4, 4)) :
  Value being assigned must be a unit

I can avoid the error by changing the line into:
g$widths[panel_index_w] <-  rep(grid:::unit.list(width), nw)

This, however, again uses grid:::unit.list(). Maybe there?s another way around
this, but turning a single width value into a unit.list seems the obvious way to
go in a case like this. So again, I?d like to request that grid:::unit.list() be
made an exported function as well. It seems quite useful any time somebody wants
to make a list of units.

Thanks!

Claus

--
Claus Wilke
Professor and Department Chair, Integrative Biology
The University of Texas at Austin
2500 Speedway, A4800
Austin, Texas 78712
512 232 2459


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