可能的重复:
这个 R 重塑应该很简单,但是 https://stackoverflow.com/questions/12829995/this-r-reshaping-should-be-simple-but
dcast
from reshape2
无需公式即可工作,不存在重复项。以这些示例数据为例:
df <- structure(list(id = c("A", "B", "C", "A", "B", "C"), cat = c("SS",
"SS", "SS", "SV", "SV", "SV"), val = c(220L, 222L, 223L, 224L,
225L, 2206L)), .Names = c("id", "cat", "val"), class = "data.frame", row.names = c(NA,
-6L))
我想dcast
这些数据只是将值制成表格,而不对value.var
包括默认的length
.
在这种情况下,效果很好。
> dcast(df, id~cat, value.var="val")
id SS SV
1 A 220 224
2 B 222 225
3 C 223 2206
但当存在重复变量时,fun
默认为length
。有办法避免吗?
df2 <- structure(list(id = c("A", "B", "C", "A", "B", "C", "C"), cat = c("SS",
"SS", "SS", "SV", "SV", "SV", "SV"), val = c(220L, 222L, 223L,
224L, 225L, 220L, 1L)), .Names = c("id", "cat", "val"), class = "data.frame", row.names = c(NA,
-7L))
> dcast(df2, id~cat, value.var="val")
Aggregation function missing: defaulting to length
id SS SV
1 A 1 1
2 B 1 1
3 C 1 2
理想情况下,我正在寻找的是添加一个fun = NA
,就像不要尝试聚合value.var
。 dcasting df2 时我想要的结果:
id SS SV
1 A 220 224
2 B 222 225
3 C 223 220
4. C NA 1