使用 dplyr::percent_rank() 计算组内的百分位数排名

假设我有以下数据：

id    grpvar1    grpvar2    value
1     1          3          7.6
2     1          2          4
...
3     1          5          2

对于每个id，我想计算percent_rank() of its value在由组合定义的组内grpvar1 and grpvar2.

Using data.table，我会去（假设我的数据位于data.frame called dataf:

library(data.table)

# Make dataset into a data.table.
dt <- data.table(dataf)

# Calculate the percentiles.
dt[, percrank := rank(value)/length(value), by = c("grpvar1", "grpvar2")]

相当于什么dplyr?

Try:

 library(dplyr)
 dataf %>%
 group_by(grpvar1, grpvar2) %>% 
 mutate(percrank=rank(value)/length(value))