align elements in ggplot

edavidaja · July 25, 2019, 1:59pm

Hi,

I'm trying to build a ggplot2 theme that will conform to my company's graphics standards. (Efforts to engineer the rules rather than the plots have been mostly unsuccessful. Alas.) The image below illustrates the main challenge I'm having: there are a number of requirements about the alignment of axis labels relative to the y-axis numbers, and the spacing of certain elements.

I can mess around with vjust and hjust for individual plots but if there's some easy way to grab the position of each of the relevant elements and snap them to the same line that would be helpful to know.

Thoughts?

mara · July 25, 2019, 2:23pm

I'm not sure I understand all of your annotations in terms of ggplot2 elements. It'd be helpful to have a reprex (a small, reproducible example) to make it easier to discuss more concretely.

Not sure if this is what you mean for one of them, but you can adjust the distance between the legend symbol and the text (see the PR where it was implemented below)

github.com/tidyverse/ggplot2

Enable margins settings for guide titles

tidyverse:master ← wilkelab:guide-title-margins

opened 02:53AM - 07 May 18 UTC

clauswilke

+427 -161

This pull request, while not completely solving https://github.com/tidyverse/ggp…lot2/issues/2465, makes it much easier to work around it, by enabling `margin`, `hjust`, and `vjust` for the theme element `legend.title`. This enables fine-grained justification control over the location of the legend title, which is needed for plots with more than one legend. Examples: ```{r} library(ggplot2) p <- ggplot(mtcars, aes(hp, disp, color = mpg, shape = factor(cyl))) + geom_point(size = 2) + theme(legend.position = "top", legend.title = element_text(vjust = 1, margin = margin(t = 4.5)), legend.spacing.y = grid::unit(3, "pt"), legend.text.align = 0.5) p ``` <img width="739" alt="screen shot 2018-05-06 at 9 39 21 pm" src="https://user-images.githubusercontent.com/4210929/39682710-2d331780-5177-11e8-9255-613295b9edcd.png"> ```{r} p + guides(shape = guide_legend(label.position = "bottom")) ``` <img width="739" alt="screen shot 2018-05-06 at 9 39 35 pm" src="https://user-images.githubusercontent.com/4210929/39682715-34120c6e-5177-11e8-9a36-4b98acc6de7e.png"> For comparison, with the default settings but legend on top, this plot looks as follows: ```{r} ggplot(mtcars, aes(hp, disp, color = mpg, shape = factor(cyl))) + geom_point(size = 2) + theme(legend.position = "top") ``` <img width="739" alt="screen shot 2018-05-06 at 9 49 27 pm" src="https://user-images.githubusercontent.com/4210929/39682770-74a78d44-5177-11e8-9b64-ffaedf5cd7a5.png"> (Unfortunately, there is no good way at this time to adjust the default settings depending on whether the legend sits on top or at the side. This will have to wait for later.) Note that none of the visual tests except one had to be changed. Things look exactly as they always did if the default settings are not changed. The visual test that had to be changed had the problem that the two legends in that plot switched order. I have now fixed the order, so this won't happen again.

Again, I could be off with what you're looking for, but in hrbrthemes, there's a flush_ticks() function that could be handy:

github.com

hrbrmstr/hrbrthemes/blob/master/R/flush-ticks.R

#' Makes axis text labels flush on the ends
#'
#' A covenience function intended for basic, fixed-scale plots only (i.e. does not handle
#' free scales in facets).\cr
#' \cr
#' You need to pass in a ggplot2 object to this function. It can't be `+`'d in a chain
#' of geoms, coords, scales, themes, etc. It also builds the plot (but does not display
#' it) so if the plt takes a while (i.e. has lots of data or transforms) this will also
#' take a while.
#'
#' @md
#' @param gg ggplot2 plot object
#' @param flush either "`X`" or "`Y`" or "`XY`" to flush individual or both axes. Default: both.
#' @param plot if `FALSE` then the ggplot object will be returned _invisibly_
#' @param cat if `TRUE` then display `theme()` statements and copy them to the clipboard
#' @return ggplot2 object with `theme()` elements added
#' @note Intended for basic, fixed-scale plots only (i.e. does not handle free scales in facets).
#' @export
flush_ticks <- function(gg, flush="XY", plot=TRUE, cat=TRUE) {

This file has been truncated. show original

mara · July 25, 2019, 2:40pm

I also highly recommend cowplot for composing figures like these! Claus is currently doing work on text for R graphics more generally, too, but cowplot great for it,

edavidaja · July 25, 2019, 2:40pm

library(ggplot2)
#> Registered S3 methods overwritten by 'ggplot2':
#>   method         from 
#>   [.quosures     rlang
#>   c.quosures     rlang
#>   print.quosures rlang
theme_acme <- list(
  theme_minimal(),
  theme(
    plot.caption = element_text(hjust = 0, size = 6),
    legend.position = "bottom",
    legend.justification = "left",
    legend.title = element_text(size = 7, face = "bold"),
    plot.title = element_text(size = 7, face = "bold"),
    axis.title.x = element_text(hjust = 0, size = 7, face = "bold"),
    axis.text = element_text(size = 7, face = "bold")
  )
)

ggplot(iris, aes(Petal.Width, Petal.Length, color = Species)) +
  geom_point() +
  labs(
    y = "",
    title = "Petal.Length",
    caption = "Source: iris data."
  ) +
  guides(color = guide_legend(ncol = 1)) +
  theme_acme

^{Created on 2019-07-25 by the reprex package (v0.3.0)}

To try state the goal more clearly: the left edges of legend.title, x.axis.title, and y.axis.title all need to be flush with the leftmost digit appearing on the y-axis.

I've been using the plot.title rather than the y.axis.title because it gets closer to the desired effect.

I will take a look at flush_ticks(), thanks for the suggestion.

system · August 15, 2019, 2:40pm

This topic was automatically closed 21 days after the last reply. New replies are no longer allowed.