New argument `data_fun` to `gglikert()`

[sda030]

This is not a huge priority for me or my colleagues, but one might want to sort not based on the proportion of categories above (or including the middle), but simply the top category. Maybe something for 0.7 or 0.8? :)

[larmarange]

I'm not sure to see the case usage.

Somehow, gglikert() cannot cover all situations, considering that for advance usage, it is possible to use directly position_likert().

Advance users can use gglikert_data() to generate a dataset or produce themselves an appropriate dataset, order factors as they need (e.g. with forcats::fct_reorder()) and finally generate a plot according to their specific needs.

library(ggstats)
library(dplyr)
#> 
#> Attachement du package : 'dplyr'
#> Les objets suivants sont masqués depuis 'package:stats':
#> 
#>     filter, lag
#> Les objets suivants sont masqués depuis 'package:base':
#> 
#>     intersect, setdiff, setequal, union
library(ggplot2)

likert_levels <- c(
  "Strongly disagree",
  "Disagree",
  "Neither agree nor disagree",
  "Agree",
  "Strongly agree"
)
set.seed(42)
df <-
  tibble(
    q1 = sample(likert_levels, 150, replace = TRUE),
    q2 = sample(likert_levels, 150, replace = TRUE, prob = 5:1),
    q3 = sample(likert_levels, 150, replace = TRUE, prob = 1:5),
    q4 = sample(likert_levels, 150, replace = TRUE, prob = 1:5),
    q5 = sample(c(likert_levels, NA), 150, replace = TRUE),
    q6 = sample(likert_levels, 150, replace = TRUE, prob = c(1, 0, 1, 1, 0))
  ) %>%
  mutate(across(everything(), ~ factor(.x, levels = likert_levels)))

tmp <- df %>% gglikert_data(include = q1:q6)

# custom sorting my data (i.e. the levels of factors to be plotted)

ggplot(tmp) +
  aes(y = .question, fill = .answer, label = scales::percent(after_stat(prop), accuracy = 1)) +
  geom_bar(position = "likert", stat = "prop") +
  geom_text(position = position_likert(.5), stat = "prop")

^{Created on 2024-03-29 with reprex v2.1.0}

[larmarange]

Eventually, we could consider an additional argument allowing to pass a custom function to be applied on the data before ploting.

[sda030]

Hi,yes, I see your point. I like the idea of a custom function in the future, or make local wrapper functions if needed.

[larmarange]

Maybe, the easiest would be to add an argument process_data = TRUE to gglikert(). If TRUE, data will be processed with gglikert_data() (as currently), if FALSE, data will be used as it, allowing to provide a custom dataset.

[sda030]

Sounds good, from the top of my mind. Let me know if you need me to test a solution.

[larmarange]

I finally adopted a data_fun argument. Please see #61