相关疑难解决方法(0)

tidyr::complete()将行添加到a data.frame中,以获取数据中缺少的列值组合.例:

library(dplyr)
library(tidyr)

df <- data.frame(person = c(1,2,2),
                 observation_id = c(1,1,2),
                 value = c(1,1,1))
df %>%
  tidyr::complete(person,
                  observation_id,
                  fill = list(value=0))

产量

# A tibble: 4 × 3
  person observation_id value
   <dbl>          <dbl> <dbl>
1      1              1     1
2      1              2     0
3      2              1     1
4      2              2     1

其中value组合person == 1和observation_id == 2缺少的组合df已填入值0.

什么相当于这个data.table？