[R] Patch for legend.position={left,top,bottom} in ggplot2

[Hadley Wickham]

Cool! Thanks Karsten. If you send me a github pull request I'll incorporate it.
Hadley

On Thursday, June 10, 2010, Karsten Loesing <karsten.loesing at gmx.net> wrote:
> Hi everyone,
>
> here's the same patch as a new branch on GitHub.
>
>   http://github.com/kloesing/ggplot2/commit/a25e4fbfa4017ed1
>
> Best,
> --Karsten
>
>
> On 6/7/10 3:39 PM, Karsten Loesing wrote:
>> Hi Hadley and everyone,
>>
>> here's a patch for ggplot2 that fixes the behavior of
>> opts(legend.position={left,top,bottom}). If you try the following code
>> in an unmodified ggplot2
>>
>> options(warn = -1)
>> suppressPackageStartupMessages(library("ggplot2"))
>> data <- data.frame(
>>     x = c(1, 2, 3, 4, 5, 6),
>>     y = c(2, 3, 4, 3, 4, 5),
>>     colour = c(TRUE, TRUE, TRUE, FALSE, FALSE, FALSE))
>> ggplot(data, aes(x = x, y = y, colour = colour)) +
>>     geom_line() + opts(title = "title", legend.position = "right")
>> ggplot(data, aes(x = x, y = y, colour = colour)) +
>>     geom_line() + opts(title = "title", legend.position = "left")
>> ggplot(data, aes(x = x, y = y, colour = colour)) +
>>     geom_line() + opts(title = "title", legend.position = "top")
>> ggplot(data, aes(x = x, y = y, colour = colour)) +
>>     geom_line() + opts(title = "title", legend.position = "bottom")
>>
>> you'll see that plots 2 to 4 are broken.
>>
>> I think I located the bug in surround_viewports() where the graphical
>> elements are placed into the grid. If we increment all rows and columns
>> of the graphical elements for positions "left", "top", and "bottom" by
>> 1, those graphs look sane again. I assume that a new first row and
>> column were added at some point in the development, but only the
>> parameters for the default position "right" were adjusted. Here's the patch:
>>
>>
>> --- ggplot2-orig2     2010-06-07 13:14:35.000000000 +0200
>> +++ ggplot2   2010-06-07 15:22:33.000000000 +0200
>> @@ -7003,27 +7003,27 @@
>>      )
>>    } else if (position == "left") {
>>      viewports <- vpList(
>> -      vp("panels", 2, 3),
>> -      vp("legend_box", 2, 1),
>> -      vp("ylabel", 2, 2),
>> -      vp("xlabel", 3, 3),
>> -      vp("title", 1, 3)
>> +      vp("panels", 3, 4),
>> +      vp("legend_box", 3, 2),
>> +      vp("ylabel", 3, 3),
>> +      vp("xlabel", 4, 4),
>> +      vp("title", 2, 4)
>>      )
>>    } else if (position == "top") {
>>      viewports <- vpList(
>> -      vp("panels", 3, 2),
>> -      vp("legend_box", 2, 2),
>> -      vp("ylabel", 3, 1),
>> -      vp("xlabel", 4, 2),
>> -      vp("title", 1, 2)
>> +      vp("panels", 4, 3),
>> +      vp("legend_box", 3, 3),
>> +      vp("ylabel", 4, 2),
>> +      vp("xlabel", 5, 3),
>> +      vp("title", 2, 3)
>>      )
>>    } else if (position == "bottom") {
>>      viewports <- vpList(
>> -      vp("panels", 2, 2),
>> -      vp("legend_box", 4, 2),
>> -      vp("ylabel", 2, 1),
>> -      vp("xlabel", 3, 2),
>> -      vp("title", 1, 2)
>> +      vp("panels", 3, 3),
>> +      vp("legend_box", 5, 3),
>> +      vp("ylabel", 3, 2),
>> +      vp("xlabel", 4, 3),
>> +      vp("title", 2, 3)
>>      )
>>    } else {
>>      viewports <- vpList(
>>
>>
>> Best,
>> --Karsten
>>
>
>

-- 
Assistant Professor / Dobelman Family Junior Chair
Department of Statistics / Rice University
http://had.co.nz/