Forthcoming ggplot2 release and esmisc

[paleolimbot]

We're in the process of preparing a ggplot2 release. As part of the release process, we run the R CMD check on packages that use ggplot2 to make sure we don't accidentally break code for downstream packages.

In running the R CMD check on esmisc, we identified the following issue:

• checking examples ... ERROR

  Running examples in ‘esmisc-Ex.R’ failed
  The error most likely occurred in:
  
  > ### Name: theme_edi
  > ### Title: Custom ggplot2 theme
  > ### Aliases: theme_edi
  > 
  > ### ** Examples
  > 
  > library(ggplot2)
  > p <- ggplot(mtcars) + 
  +  geom_point(aes(x = wt, y = mpg, 
  + colour=factor(gear))) + facet_wrap(~am)
  > p
  > p + theme_edi()
  Error in axis.ticks.length.x.bottom %||% axis.ticks.length.x : 
    object 'axis.ticks.length.x.bottom' not found
  Calls: <Anonymous> ... with -> with.default -> eval -> eval -> %||% -> %||%
  Execution halted
  

As part of the new release, we improved the theme() function to allow different lengths of ticks on the top and bottom of the plot. As a result, theme_edi() in esmisc is no longer complete, as it does not inherit from a current ggplot2 theme (like theme_grey()). We recommend using code like the following to define new themes, so that we can continue to improve the ggplot2 theme system without breaking others' code:

# Starts with theme_grey and then modify some parts 
 ggplot2::theme_grey( 
   base_size = base_size, 
   base_family = base_family, 
   base_line_size = base_line_size, 
   base_rect_size = base_rect_size 
 ) %+replace% 
  ggplot2::theme(...)

For this to work, you will have to import %+replace% into your package namespace, which you can do by adding the following line to any roxygen documentation block:

#' @importFrom ggplot2 %+replace%

Let us know if we can help! We are hoping to release the next version of ggplot2 in the next two weeks.