r - 将 data.table/data.frame 与部分匹配的矩阵匹配

Question

我正在尝试合并以下 data.table:

DE <- structure(list(date1 = c("2000", "2001", "2003"), country = c("DE", 
"DE", "DE"), value = c(10, 20, 30)), row.names = c(NA, -3L), class = c("data.table", 
"data.frame"))

   date1 country value
1:  2000      DE    10
2:  2001      DE    20
3:  2003      DE    30 

我想将它与一个带 0 的矩阵合并:

df <- structure(c(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0), .Dim = 6:5, .Dimnames = list(
    c("2000", "2001", "2002", "2003", "2004", "2005"), c("UK", 
    "DE", "FR", "SP", "IT")))

     UK DE FR SP IT
2000  0  0  0  0  0
2001  0  0  0  0  0
2002  0  0  0  0  0
2003  0  0  0  0  0
2004  0  0  0  0  0
2005  0  0  0  0  0

这样所需的输出如下:

     UK DE  FR SP IT
2000  0  10  0  0  0
2001  0  20  0  0  0
2002  0  0   0  0  0
2003  0  30  0  0  0
2004  0  0   0  0  0
2005  0  0   0  0  0

Answer 1

我们可以使用行/列索引将“value”列从“DE”分配给“df”

df[DE$date1, DE$country] <- DE$value

-输出

> df
     UK DE FR SP IT
2000  0 10  0  0  0
2001  0 20  0  0  0
2002  0  0  0  0  0
2003  0 30  0  0  0
2004  0  0  0  0  0
2005  0  0  0  0  0