如何在函数内添加函数？ [英] How to add a function within a function?

问题描述

我具有创建绘图的功能。但是，我想在函数中进行一些预处理，以使用 sjlabelled 包将值转换为标签。

I have a function to create a plot. However, I would like to include some preprocessing within the function to convert values to labels using the sjlabelled package.

library(haven)
data <- read_spss("http://staff.bath.ac.uk/pssiw/stats2/SAQ.sav")

library(dplyr)
library(labelled)
library(sjlabelled)

bar_plot <- function(data, var) {
  
  data %>% 
    as_label(var) %>% 
    filter({{var}} != "Neither") %>% 
    ggplot(aes({{var}})) +
    geom_bar() +
    coord_flip() +
    theme_classic() +
    labs(x = NULL, y = "Count", title = var_label(pull(data, {{var}})))
}

bar_plot(data, Q01)

我正在获取绘图，但它是不正确的，并且在控制台中出现此错误在数据集中未找到1个变量：var

I'm getting a plot but it is incorrect and I get this error in the console 1 variables were not found in the dataset: var

我尝试使用 curly-curly ， eval ， !! ， sym ， ensym ，但没有一个起作用。

I tried using curly-curly, eval, !!, sym, ensym, but none of them worked.

问题在于此行： as_label （var）％>％

推荐答案

问题是 as_label 函数使用删除并替换您可以自己查看该函数： sjlabelled ::: as_label.data.frame 或调用它

The issue is that the as_label function captures user input with deparse and substitute You can take a look at the function yourself: sjlabelled:::as_label.data.frame, or call it with debug.

要解决此问题，可以结合使用 do.call 和 ensym （ enexpr 也可以）。

To get around this, you can use a combination of do.call and ensym (enexpr also works).

bar_plot <- function(data, var) {

  data <- do.call(as_label, list(data, ensym(var)))
  
  data %>% 
    filter({{ var }} != "Neither") %>% 
    ggplot(aes({{ var }})) +
    geom_bar() +
    coord_flip() +
    theme_classic() +
    labs(x = NULL, y = "Count", title = var_label(pull(data, {{ var }})))
}


data %>% bar_plot(Q01)

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