重塑计数变量

Question

我有这样的数据：

structure(list(ID = 1:4, concept = c("a", "b", "c", "d"), count = c(1L, 
2L, 4L, 6L)), class = "data.frame", row.names = c(NA, -4L))

如何重塑数据以：

ID  a   b   c   d
1   1   0   0   0
2   0   2   0   0
3   0   0   4   0
4   0   0   0   6

Answer 1

您可以使用以下代码：

df <- structure(list(ID = 1:4, concept = c("a", "b", "c", "d"), count = c(1L, 
                                                                          2L, 4L, 6L)), class = "data.frame", row.names = c(NA, -4L))

library(reshape2)
dcast(df, ID ~ concept, value.var = "count", fill = 0)
#>   ID a b c d
#> 1  1 1 0 0 0
#> 2  2 0 2 0 0
#> 3  3 0 0 4 0
#> 4  4 0 0 0 6

^{在2022-07-08创建的 reprex package （v2（v2）。 0.1）}