r - Sparklyr 使用 case_when 和变量

Question

case_when使用带有外部变量的 a 时，Sparklyr 失败。

工作示例：

test <- copy_to(sc, tibble(column = c(1,2,3,4)))
test %>%
  mutate(group = case_when(
                   column %in% c(1,2) ~ 'group 1',
                   column %in% c(3,4) ~ 'group 2'))

失败Error: Can't extract an environment from NULL

test <- copy_to(sc, tibble(column = c(1,2,3,4)))
group1_cols <- c(1,2)
group2_cols <- c(3,4)
test %>%
  mutate(group = case_when(
                   column %in% group1_cols ~ 'group 1',
                   column %in% group2_cols ~ 'group 2'))

Answer 1

尝试取消引用变量：

test %>%
  mutate(group = case_when(
    column %in% !!group1_cols ~ 'group 1',
    column %in% !!group2_cols ~ 'group 2'))

有关更多信息，请查看dplyr编程小插图http://dplyr.tidyverse.org/articles/programming.html