What is the R equivalent to Stata's fillin?

Question

Stata's fillin command makes a dataset rectangular. How can I do the same in R ?

As a reproducible example, say that I have the data below:

data <- data.frame(season = c("2016-17","2017-18","2018-19", "2018-19"), group=c("A","A","A","B"), value=c(1,2,3,6)) 

I would like to get the following:

data_wanted <- data.frame(season = c("2016-17","2017-18","2018-19", "2018-19", "2016-17", "2017-18"), group=c("A","A","A","B","B","B"),value=c(1,2,3,6,NA,NA))

Answer 1

使用tidyr::complete ，只需要指定季节和组的每个组合即可：

tidyr::complete(data, season, group)