通过用户定义的截止将帧拆分为列表

Question

想通过cutoff 将df框架拆分为嵌套df.listing列表index_cutoff:

数据:

df <- data.frame(m=c("A","T","W","Z","B","A","A","W","T","K","G","B","T","B"))
index_cutoff <- c("A","B")

尝试代码:

df.listing <- split(df, df$m %in% keyword_cutoff) #failed, not working

电流输出:

$`FALSE`
   m
2  T
3  W
4  Z
8  W
9  T
10 K
11 G
13 T

$`TRUE`
   m
1 A
5 B
6 A
7 A
12 B
14 B

期望的输出阶段1:

df.listing[[1]]
A
T
W
Z

df.listing[[2]]
B

df.listing[[3]]
A

df.listing[[4]]
A
W
T
K
G

df.listing[[5]]
B
T

df.listing[[6]]
B

期望的输出最终:

df.listing[[1]]
A
T
W
Z

df.listing[[2]]
B

df.listing[[3]]
A #since at stage 1 they are the same cutoff, hence self merge into next list
A
W
T
K
G

df.listing[[4]]
B #since at stage 1 they begin the same with "B" cutoff
T
B

感谢您并且不能通过R数据集提供可重现的示例.

Answer 1

我们需要将逻辑索引的累积和作为拆分组

split(df, cumsum(df$m %in% index_cutoff))

在OP的代码中,只有两个组,即TRUE和FALSE df$m %in% index_cutoff.通过这样做cumsum,它通过在每个TRUE值加1来改变