所以我有 9 列
a b c d e f g h i
1 1 t p 1 h p 1 v g
2 2 e h 2 j m 2 c f
3 3 f g 3 k l 3 b d
我想知道如何让它们像这样
a b c
1 1 t p
2 2 e h
3 3 f g
4 1 h p
5 2 j m
6 3 k l
7 1 v g
8 2 c f
9 3 b d
最佳答案
我们可以通过指定要在向量的列表中组合在一起的列来使用base R中的reshape
out <- reshape(df1, direction = 'long',
varying = list(c('a', 'd', 'g'), c('b', 'e', 'h'),
c('c', 'f', 'i')))[c('a', 'b', 'c')]
row.names(out) <- NULL
out
# a b c
#1 1 t p
#2 2 e h
#3 3 f g
#4 1 h p
#5 2 j m
#6 3 k l
#7 1 v g
#8 2 c f
#9 3 b d
或者使用data.table中的melt
library(data.table)
melt(setDT(df1), measure = list(c('a', 'd', 'g'), c('b', 'e', 'h'),
c('c', 'f', 'i')), value.name = c('a', 'b', 'c'))[, variable := NULL][]
数据
df1 <- structure(list(a = 1:3, b = c("t", "e", "f"), c = c("p", "h",
"g"), d = 1:3, e = c("h", "j", "k"), f = c("p", "m", "l"), g = 1:3,
h = c("v", "c", "b"), i = c("g", "f", "d")),
class = "data.frame", row.names = c("1",
"2", "3"))
关于r - 合并多列/堆叠多列，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/60872813/