我正在使用与此类似的数据框：
df1 <- data.frame(p1 = c("John", "John", "John", "John", "John", "John", "Jim", "Jim", "Jim", "Jim", "Jim", "Jim", "Jim","Jim" ),
elapsed_time = c(0, 4, 6, 9, 12, 14, 17, 22, 27, 35, 42, 47, 51, 57),
event_type = c("start of period", "play", "play", "play", "play", "play", "play", "play", "play", "timeout", "play", "play", "play", "play"))
看起来像这样：
p1 elapsed_time event_type
1 John 0 start of period
2 John 4 play
3 John 6 play
4 John 9 play
5 John 12 play
6 …