R中的函数给出ggplot输出错误

Question

样本数据：

df <- tibble(
 "PLAYER" = c("Corey Kluber", "CLayton Kershaw", "Max Scherzer", "Chris Sale",
           "Corey Kluber", "Jake Arrieta", "Jose Urena", "Yu Darvish"),
 "YEAR" = c(2016, 2016, 2016, 2016, 2017, 2017, 2017, 2017),
 "WHIP" = c(1.24, 1.50, 1.70, 1.35, 1.42, 1.33, 1.61, 1.10),
 "ERA" =  c(3.27, 4.0, 2.56, 1.45, 3.87, 4.23, 3.92, 2.0)
)

数据集要大得多，但我写了一个函数（不起作用）来检索玩家和所需的统计数据，然后使用ggplot 输出一个绘图：

baseball_stats <- function(player, statistic) {

  # Libraries
  library(tidyverse)
  library(rvest)
  library(ggrepel)

  # Function to set YEAR scale to number of seasons played by pitcher
  f <- function(k) {
    step <- k
    function(y) seq(floor(min(y)), ceiling(max(y)), by = step)
   }

  # ggplot of player and chosen statistic
  p <- df %>% 
    group_by(PLAYER) %>% 
    filter(PLAYER == player) %>% 
    ggplot() +
    geom_col(aes(YEAR, statistic), width = .5) +
    scale_x_continuous(breaks = f(1)) +  # Uses the function to set YEAR breaks
    scale_y_continuous(breaks = f(0.1)) +
    theme_bw() +
  coord_flip() +
  labs(
   title = "statistic Statistic: player",
   subtitle = "statistic over seasons played",
   x = "Year",
   y = "statistic Stat",
   caption = "Data from espn.com")

  print(p)
  return(baseball_stats)

}

baseball_stats("Corey Kluber", WHIP)

我得到Error: Discrete value supplied to continuous scale 或另一个关于$ 和原子向量的错误（我的数据集是使用rvest 抓取的，我必须清理它，我试图将它包含在我的函数中）。谢谢

Answer 1

将aes更改为aes_string后得到了一个情节

geom_col(aes_string("YEAR", statistic), width = .5)

请注意YEAR 在引号中。我将其称为以下命令

baseball_stats("Corey Kluber", "WHIP")

WHIP 也是在 quot 中传递的。

完整代码在这里：

baseball_stats <- function(player, statistic) {

  # Libraries
  library(tidyverse)
  library(rvest)
  library(ggrepel)

  # Function to set YEAR scale to number of seasons played by pitcher
  f <- function(k) {
    step <- k
    function(y) seq(floor(min(y)), ceiling(max(y)), by = step)
  }

  # ggplot of player and chosen statistic
  p <- df %>% 
    group_by(PLAYER) %>% 
    filter(PLAYER == player) %>% 
    ggplot() +
    geom_col(aes_string("YEAR", statistic), width = .5) +
    scale_x_continuous(breaks = f(1)) +  # Uses the function to set YEAR breaks
    scale_y_continuous(breaks = f(0.1)) +
    theme_bw() +
    coord_flip() +
    labs(
      title = "statistic Statistic: player",
      subtitle = "statistic over seasons played",
      x = "Year",
      y = "statistic Stat",
      caption = "Data from espn.com")

  print(p)
  return(baseball_stats)

}

baseball_stats("Corey Kluber", "WHIP")