拆分列表每 n 个元素和 cbind，然后是 rbind 切片

Question

我想对列表的每个 n 个元素进行切片，cbind 切片，然后 rbind 切片。

我可以用下面的代码来做到这一点（n = 10 个元素，列表有 30 个元素长）。我 'manually' select 列表的每 10 个元素，然后 cbind 这 10 个元素切片。然后我 rbind 那些 cbinded 切片。

但是，我认为 plyr 或 dplyr 中的 l*ply 或至少其中的一部分可能有解决此问题的方法。对于初学者，我现在不知道如何 select 列表的每个 n 个元素，并且似乎不知道合适的搜索词来找到这个答案。

dl <- list(c(2L, 1L, 3L, 2L, 1L, 1L, 3L), c(1L, 1L, 2L, 1L, 1L, 2L, 
1L), c(1L, 1L, 2L, 2L, 3L, 3L, 3L), c(1L, 1L, 2L, 2L, 3L, 3L, 
3L), c(1L, 1L, 2L, 2L, 3L, 3L, 3L), c(1L, 1L, 2L, 2L, 3L, 3L, 
1L), c(1L, 1L, 2L, 2L, 3L, 3L, 3L), c(1L, 3L, 2L, 1L, 3L, 2L, 
1L), c(3L, 1L, 2L, 3L, 3L, 1L, 3L), c(3L, 2L, 1L, 1L, 3L, 3L, 
1L), c(1L, 1L, 2L, 2L, 2L, NA, NA), c(1L, 1L, 2L, 2L, 3L, NA, 
NA), c(1L, 1L, 2L, 2L, 3L, NA, NA), c(1L, 1L, 2L, 2L, 3L, NA, 
NA), c(1L, 1L, 2L, 2L, 3L, NA, NA), c(1L, 1L, 2L, 2L, 3L, NA, 
NA), c(1L, 1L, 2L, 2L, 3L, NA, NA), c(1L, 1L, 2L, 2L, 3L, NA, 
NA), c(1L, 1L, 2L, 2L, 3L, NA, NA), c(2L, 1L, 2L, 1L, 1L, NA, 
NA), c(2L, 3L, 1L, 2L, 1L, 2L, NA), c(1L, 1L, 2L, 2L, 1L, 3L, 
NA), c(1L, 1L, 2L, 2L, 3L, 3L, NA), c(1L, 1L, 2L, 2L, 3L, 3L, 
NA), c(1L, 1L, 2L, 2L, 3L, 3L, NA), c(1L, 1L, 2L, 2L, 3L, 3L, 
NA), c(1L, 1L, 2L, 2L, 3L, 3L, NA), c(1L, 1L, 2L, 2L, 3L, 3L, 
NA), c(1L, 1L, 2L, 2L, 3L, 3L, NA), c(1L, 1L, 2L, 2L, 3L, 3L, 
NA)) 

# slice list 'manually' cbind those slices
dl1 <- dl[1:10]
dl1.c <- do.call("cbind", dl1)
dl2 <- dl[11:20]
dl2.c <- do.call("cbind", dl2)
dl3 <- dl[21:30]
dl3.c <- do.call("cbind", dl3)

# rbind the cbind slices for result
ans <- as.data.frame(rbind(dl1.c, dl2.c, dl3.c)) # ans as df
# ans <- rbind(dl1.c, dl2.c, dl3.c)

Answer 1

尝试

do.call(mapply, c(cbind, split(dl, cut(seq_along(dl), length(dl)/10, labels = FALSE))))

拆分列表每 n 个元素和 cbind，然后是 rbind 切片

Split list every n elements and cbind, then rbind slices

r

list

rbind

cbind

dplyr