使用动态列名在 dplyr 中按自定义顺序排列

Question

我正在尝试根据某个列排列小标题（但根据变量动态设置的名称设置列）。

以下是我目前正在尝试但出现错误的代码。第二次粘贴代码有效（我在符号的列名中硬编码了我想根据变量设置的符号）。

library(tidyverse)

group_var <- "symbol"

date_seq <- seq(as.Date("2000-01-01"), as.Date("2009-12-31"), by = "days")
test_tbl <- tibble::tibble("date" = rep(date_seq, 3),
                           "symbol" = rep(c("test3", "test1", "test2"), each = length(date_seq)),
                           "value" = c(rnorm(length(date_seq), sd = 0.05),
                                       rnorm(length(date_seq), sd = 0.05),
                                       rnorm(length(date_seq), sd = 0.05)))

order_var <- c("test1", "test2", "test3")
test_tbl_final <- test_tbl %>%
  dplyr::arrange(factor(!!group_var, levels = order_var), date)

以下是有效的代码并显示了我要完成的工作：

library(tidyverse)

date_seq <- seq(as.Date("2000-01-01"), as.Date("2009-12-31"), by = "days")
test_tbl <- tibble::tibble("date" = rep(date_seq, 3),
                           "symbol" = rep(c("test3", "test1", "test2"), each = length(date_seq)),
                           "value" = c(rnorm(length(date_seq), sd = 0.05),
                                       rnorm(length(date_seq), sd = 0.05),
                                       rnorm(length(date_seq), sd = 0.05)))

order_var <- c("test1", "test2", "test3")
test_tbl_final <- test_tbl %>%
  dplyr::arrange(factor(symbol, levels = order_var), date)

Answer 1

您也可以使用来自基本 R 的as.symbol

test_tbl_final <- test_tbl %>%
  dplyr::arrange(factor(!!as.symbol(group_var), levels = order_var), date)

Answer 2

您需要rlang:sym 将group_var 从字符symbol 转换为符号symbol，然后使用!! 将符号评估为列对象：

test_tbl %>% 
    arrange(factor(!!rlang::sym(group_var), levels = order_var), date)

# A tibble: 10,959 x 3
#         date symbol         value
#       <date>  <chr>         <dbl>
# 1 2000-01-01  test1  0.0519143671
# 2 2000-01-02  test1 -0.0464782439
# 3 2000-01-03  test1 -0.0295441613
# ...