ggplot 代码和带有 ggplot 的函数不提供相同的结果

Question

我在创建包含 ggplot 的函数时遇到问题。当我在函数外执行代码时，它会生成我想要的情节，但在函数内它会生成不同的情节......我不确定我做错了什么......

我复制下面带有示例数据库的reprex：

library(tidyverse)
#> Warning: package 'tidyverse' was built under R version 4.0.5
#> Warning: package 'ggplot2' was built under R version 4.0.5
#> Warning: package 'tibble' was built under R version 4.0.5
#> Warning: package 'tidyr' was built under R version 4.0.5
#> Warning: package 'readr' was built under R version 4.0.5
#> Warning: package 'purrr' was built under R version 4.0.5
#> Warning: package 'dplyr' was built under R version 4.0.5
#> Warning: package 'stringr' was built under R version 4.0.5
#> Warning: package 'forcats' was built under R version 4.0.5
library(ggplot2)

# Example data 
wb <- data.frame(country = c("Antigua and Barbuda", "Belize", "Costa Rica", "Dominica", "Dominican Republic",
                             "El Salvador", "Guyana", "Guatemala", "Haiti", "Honduras", "Jamaica", "Nicaragua", 
                             "Panama", "Surinam", "Trinidad and Tobago"), 
                 income = factor(c("high", "low", "upper-middle","upper-middle", "upper-middle", 
                                   "lower-middle", "upper-middle", "upper-middle","low", NA, "upper-middle",
                                   "lower-middle", "high", "upper-middle", "high")),
                 group = c("A", "C", "B","C", "B","B", "B", "C","B", "A", "B","C", "C", "B", "A"),
                 stringsAsFactors = FALSE)


# I execute  the folowing code to create a plot (I do not execute it now because I do not have enough reputation in the forum to do it): 
df <- wb %>% 
  drop_na(income) %>%
  group_by(group,income) %>% 
  tally() %>% 
  complete(income, fill = list(n = 0)) %>% 
  mutate(percentage = n / sum(n) * 100)

ggplot(df, aes(income, percentage, fill = group)) + 
  geom_bar(stat = 'identity', position = 'dodge') +
  scale_y_continuous("Title Y", expand = c(0,0))+ 
  scale_x_discrete("Title X")+ 
  scale_fill_manual("Title of legend", values = c("#15607a", "#18a1cd", "cyan")) +
  theme_classic(base_size=11) + 
  theme(axis.text.x = element_text(angle = 0, 
                                   hjust = 1, vjust = 0),
        axis.line = element_blank(),
        axis.ticks.x = element_blank(), 
        legend.title = element_text(colour = "#00344c", size = 8, face = "bold")) 

# Now I try to create a function to automatize the previous plot 

create_graph <- function(x,y,t){
  df <- wb %>% 
    drop_na({{y}}) %>%
    group_by({{x}},{{y}}) %>% 
    tally() %>% 
    complete({{y}}, fill = list(n = 0)) %>% 
    mutate(percentage = n / sum(n) * 100)
  
  ggplot(df, aes(y, percentage, fill = x)) + 
    geom_bar(stat = 'identity', position = 'dodge') +
    scale_y_continuous("Title Y", expand = c(0,0))+ 
    scale_x_discrete(t)+ 
    scale_fill_manual("Title of legend", values = c("#15607a", "#18a1cd", "cyan")) +
    theme_classic(base_size=11) + 
    theme(axis.text.x = element_text(angle = 0, 
                                     hjust = 1, vjust = 0),
          axis.line = element_blank(),
          axis.ticks.x = element_blank(), 
          legend.title = element_text(colour = "#00344c", size = 8, face = "bold")) 
}

# When I execute the function alone, the resulting plot it's not the same as the plot coded above: 
create_graph(x = "income", 
             y = "group",
             t = "Funny title")

^{由reprex package (v2.0.0) 于 2021-04-22 创建}

非常感谢！

Answer 1

几个观察：

• 在 create_graph() 调用中，如果您使用 curly-curly {{..}} 包装器进行非标准评估，则无需引用变量名。
• 在 create_graph() 函数中，我认为您可能已经相对于示例图交换了一些 x 和 ys。
• 在 aes(...) 调用中，您还可以使用 curly-curly 包装器。

以下是我如何获得函数以返回示例图作为示例：

library(tidyverse)
library(ggplot2)

# Example data 
wb <- data.frame(country = c("Antigua and Barbuda", "Belize", "Costa Rica", "Dominica", "Dominican Republic",
                             "El Salvador", "Guyana", "Guatemala", "Haiti", "Honduras", "Jamaica", "Nicaragua", 
                             "Panama", "Surinam", "Trinidad and Tobago"), 
                 income = factor(c("high", "low", "upper-middle","upper-middle", "upper-middle", 
                                   "lower-middle", "upper-middle", "upper-middle","low", NA, "upper-middle",
                                   "lower-middle", "high", "upper-middle", "high")),
                 group = c("A", "C", "B","C", "B","B", "B", "C","B", "A", "B","C", "C", "B", "A"),
                 stringsAsFactors = FALSE)

create_graph <- function(x,y,t){
  df <- wb %>% 
    drop_na({{x}}) %>%
    group_by({{y}},{{x}}) %>% 
    tally() %>% 
    complete({{x}}, fill = list(n = 0)) %>% 
    mutate(percentage = n / sum(n) * 100)
  
  ggplot(df, aes({{x}}, percentage, fill = {{y}})) + 
    geom_bar(stat = 'identity', position = 'dodge') +
    scale_y_continuous("Title Y", expand = c(0,0))+ 
    scale_x_discrete(t)+ 
    scale_fill_manual("Title of legend", values = c("#15607a", "#18a1cd", "cyan")) +
    theme_classic(base_size=11) + 
    theme(axis.text.x = element_text(angle = 0, 
                                     hjust = 1, vjust = 0),
          axis.line = element_blank(),
          axis.ticks.x = element_blank(), 
          legend.title = element_text(colour = "#00344c", size = 8, face = "bold")) 
}

create_graph(x = income, 
             y = group,
             t = "Funny title")

^{由reprex package (v1.0.0) 于 2021 年 4 月 22 日创建}

旁注：如果您将第二个参数命名为 y，人们可能会认为 y 是出现在 y 轴上的内容，而您的绘图中并非如此。