README.md

In EvaMaeRey/ggdirect:

• ggdirect (likely to be superceded by ggbarlabs)
• Problem:
  • bar charts are ubiquitous and can quickly communicate information.
  • bar plots can benefit from specificity of labeling
  • but its a pain
  • or use verbose after_stat…
    • first inspecting bar layer (stat_count)
    • then plot
  • Proposed User interface
  • Composing functions
    • geom_text_count
    • Try it out
    • geom_text_count_percent
    • Try it out
• Furthermore, a different set of thematic and scale defaults make sense for labeled bar charts
• lets put all of this in ggbarlabs()
  • try it out
  • Issues
    • vjust may give us better results than nudge_y…
    • move ggbarlabs()
    • percents is calculated within panel. We might want to specify the ‘whole’ from which percentage is calculated.
    • horizontal bars

ggdirect (likely to be superceded by ggbarlabs)

Problem:

bar charts are ubiquitous and can quickly communicate information.

library(ggplot2)
theme_set(theme_gray(18))
ggplot(mtcars) + 
  aes(x = am) + 
  geom_bar() 

p <- last_plot()

bar plots can benefit from specificity of labeling

Labeled bar chart is all the fast communication of traditional data vizualization with all the specificity of a table.

but its a pain

either precalc and use geom_col + geom_text

or use verbose after_stat…

first inspecting bar layer (stat_count)

layer_data(last_plot(), 1)
#>    y count    prop x flipped_aes PANEL group ymin ymax  xmin xmax colour   fill
#> 1 19    19 0.59375 0       FALSE     1    -1    0   19 -0.45 0.45     NA grey35
#> 2 13    13 0.40625 1       FALSE     1    -1    0   13  0.55 1.45     NA grey35
#>   linewidth linetype alpha
#> 1       0.5        1    NA
#> 2       0.5        1    NA

then plot

using our knowledge of what data frame results when using StatCount, refer to the computed var, count

# count column can be used via after_stat
p +
  geom_text(stat = StatCount, 
            aes(label = after_stat(count)), 
            vjust = -.7)

p + 
  geom_text(stat = StatCount, 
            aes(label = after_stat(
              paste0(round(100*count/sum(count), 1) ,"%")
              )), 
            vjust = -.7)

p + 
  geom_text(stat = StatCount, 
            aes(label = after_stat(
              paste0(count,"\n(",round(100*count/sum(count), 1) ,"%)")
              )), 
            vjust = -.5, lineheight = .8)

layer_data(last_plot(), 2)
#>         label  y count    prop x width flipped_aes PANEL group colour size
#> 1 19\n(59.4%) 19    19 0.59375 0   0.9       FALSE     1    -1  black 3.88
#> 2 13\n(40.6%) 13    13 0.40625 1   0.9       FALSE     1    -1  black 3.88
#>   angle hjust vjust alpha family fontface lineheight
#> 1     0   0.5  -0.5    NA               1        0.8
#> 2     0   0.5  -0.5    NA               1        0.8

Proposed User interface

ggplot(mtcars) + 
  aes(x = am) + 
  geom_bar() 

ggplot(mtcars) + 
  aes(x = am) + 
  geom_bar() + 
  geom_text_count()

ggplot(mtcars) + 
  aes(x = am) + 
  geom_bar() + 
  geom_text_count_percent()

Composing functions

geom_text_count

#' geom_text_count
#' @description Add label which is the count.  Acts like geom_bar() but text label at the position of the top of the bar.
#'
#' @param nudge_y
#' @param position
#' @param ...
#'
#' @return
#' @export
#'
#' @examples
#' library(ggplot2)
#' ggplot(mtcars) +
#'    aes(x = cyl) +
#'    geom_bar() +
#'    geom_text_count(nudge_y = .5)
geom_text_count <- function(nudge_y = 0, position =
                              ggplot2::position_dodge2(width = .9,
                                                       preserve = "single"), ...){

  ggplot2::stat_count(geom = "text",
                      ggplot2::aes(label = ggplot2::after_stat(count),
                                   y = ggplot2::after_stat(count) + nudge_y),
                      vjust = 0,
                      position = position,
                      ...
  )

}

Try it out

library(ggplot2)
ggplot(mtcars) +
   aes(x = factor(cyl)) +
   geom_bar(position = "dodge") +
   geom_text_count(nudge_y = .2)

last_plot() + 
  aes(fill = factor(am))

geom_text_count_percent

#' geom_text_count_percent
#' @description Add label which is the count as well as percentage.  Acts like geom_bar() but text label at the position of the top of the bar.  Percentage is calculated within facet panels.
#'
#' @param nudge_y
#' @param lineheight
#' @param position
#' @param ...
#'
#' @return
#' @export
#'
#' @examples
#' library(ggplot2)
#' ggplot(mtcars) +
#'     aes(x = cyl) +
#'     geom_bar() +
#'     geom_text_count_percent(nudge_y = .5)
geom_text_count_percent <- function(nudge_y = 0,
                                    lineheight = .85,
                                    position = ggplot2::position_dodge2(width = .9,
                                                               preserve = "single"), ...){

  stat_count(geom = "text",
             ggplot2::aes(label = paste0(after_stat(count), "\n(",

                                round(
                                  100*(ggplot2::after_stat(count))/
                                    tapply(ggplot2::after_stat(count),
                                           ..PANEL..,
                                           sum)[..PANEL..],
                                  1), "%)" ),
                 y = ggplot2::after_stat(count) + nudge_y),
             vjust = 0,
             lineheight = lineheight,
             position = position,
             ...
             )
}

Try it out

library(ggplot2)
ggplot(mtcars) +
    aes(x = factor(cyl)) +
    geom_bar(position = "dodge") +
    geom_text_count_percent(nudge_y = .25)
#> Warning: The dot-dot notation (`..PANEL..`) was deprecated in ggplot2 3.4.0.
#> ℹ Please use `after_stat(PANEL)` instead.
#> This warning is displayed once every 8 hours.
#> Call `lifecycle::last_lifecycle_warnings()` to see where this warning was
#> generated.

last_plot() +
    aes(fill = factor(am))

Furthermore, a different set of thematic and scale defaults make sense for labeled bar charts

ggplot(mtcars) +
  aes(x = factor(cyl)) +
  geom_bar(position = "dodge") +
  geom_text_count(nudge_y = .2) +
  theme_classic() +
  theme(axis.line.y = element_blank(),
        axis.text.y.right = element_blank(),
        axis.ticks.y = element_blank(),
        axis.title.y = element_blank(),
        axis.text.y = element_blank(),
        panel.grid.major.y = element_line(color = alpha("gray35", .25)),
        panel.grid.major.x = element_blank(),
        panel.grid.minor.x = element_blank(),
        axis.line.x = element_line(colour = "gray35"),
        legend.position = "top",
        legend.justification = 0) +
  scale_y_continuous(expand = expansion(mult = c(0, .1)))

lets put all of this in ggbarlabs()

ggbarlabs <- function(data = NULL, ...){
  ggplot(data= data , ... ) +
  theme_classic(base_size = 15) +
  theme(axis.line.y = element_blank(),
        axis.text.y.right = element_blank(),
        axis.ticks.y = element_blank(),
        axis.title.y = element_blank(),
        axis.text.y = element_blank(),
        panel.grid.major.y = element_line(color = alpha("gray35", .25)),
        panel.grid.major.x = element_blank(),
        panel.grid.minor.x = element_blank(),
        axis.line.x = element_line(colour = "gray35"),
        legend.position = "top",
        legend.justification = 0) +
  scale_y_continuous(expand = expansion(mult = c(0, .15)))
}

try it out

ggbarlabs(mtcars) + 
  aes(x = factor(am)) + 
  geom_bar(fill = alpha("navy", .9)) + 
  geom_text_count_percent()

ggbarlabs(mtcars) + 
  aes(x = factor(am), fill = factor(cyl)) + 
  geom_bar(position = "dodge") + 
  geom_text_count_percent()

Issues

vjust may give us better results than nudge_y…

move ggbarlabs()

percents is calculated within panel. We might want to specify the ‘whole’ from which percentage is calculated.

horizontal bars

EvaMaeRey/ggdirect documentation built on Sept. 29, 2023, 12:36 a.m.