如何使用 tidyevaluate 将对象名称作为字符串获取？

Question

我需要将列名传递给绘图函数。问题是我的列名在参数中，我不知道如何将它们提取为文本。

这是有效的代码，但我需要从参数中动态获取字符串。

create_plot <- function(df, group, subgroup, y){
  var_group <- enquo(group)
  var_subgroup <- enquo(subgroup)
  var_y <- enquo(y)
  df %>% 
    select(!!var_group, !!var_subgroup, !!var_y) %>% 
    mutate(!!var_group := as.factor(!!var_group),
           !!var_subgroup := as.factor(!!var_subgroup)) %>% 
    ggsummarystats(., x = "COUNTRY", y="VALUE", # Need to get these from the arguments
                   palette = custom_pal,
                   ggfunc = ggboxplot,
                   color = "YEAR",  #Same here
                   fill = "YEAR",  #And here
                   summaries = c("n", "mean"))
}

create_plot(sales, YEAR, COUNTRY, VALUE)

使用 mtcars 的示例：

create_plot <- function(df, group, subgroup, y){
    var_group <- enquo(group)
    var_subgroup <- enquo(subgroup)
    var_y <- enquo(y)
    df %>% 
      select(!!var_group, !!var_subgroup, !!var_y) %>% 
      mutate(!!var_group := as.factor(!!var_group),
             !!var_subgroup := as.factor(!!var_subgroup)) %>% 
      ggsummarystats(., x = "carb", y="mpg",
                     palette = custom_pal,
                     ggfunc = ggboxplot,
                     fill = "gear",
                     color = "gear",
                     summaries = c("n", "mean"))
  }

create_plot(mtcars, gear, carb, mpg)

Answer 1

您可以使用 rlang::as_name()：

library(tidyverse)
library(rlang)
library(ggpubr)


create_plot <- function(df, group, subgroup, y){
  
  var_group <- enquo(group)
  var_subgroup <- enquo(subgroup)
  var_y <- enquo(y)
  
  df %>% 
    select(!!var_group, !!var_subgroup, !!var_y) %>%
    mutate(
      !!var_group := as.factor(!!var_group),
      !!var_subgroup := as.factor(!!var_subgroup)
    ) %>%
    ggsummarystats(
      x = as_name(var_group), 
      y = as_name(var_y),
      fill = as_name(var_subgroup),
      ggfunc = ggboxplot, 
      summaries = c("n", "mean"))
}

create_plot(mtcars, gear, carb, mpg)

^{由 reprex package (v1.0.0)}

于 2021 年 6 月 14 日创建

如何使用 tidyevaluate 将对象名称作为字符串获取？

How to get object name as a string using tidyevaluate?

r

ggplot2

tidyeval

ggpubr