R中如何设置占位符

Question

df1 <- 
structure(c(3L, NA, 3L, 3L, 3L, 2L, 3L, 2L, 2L, 2L, 3L, 3L, 2L, 
2L, 3L, 3L, 3L, 3L, 3L, 3L, 2L, 1L, 3L, 1L, 3L, 3L, 3L, 3L, 3L, 
3L, 3L, 3L, 2L, 1L, 2L, 3L, 3L, 2L, 3L, 3L, 3L, 3L, 2L, 1L, 3L, 
2L, 2L, 3L, 2L, 3L, 3L, 3L, 3L, 2L, 2L, 2L, 3L, 3L, 3L, 2L, 3L, 
3L, 1L, 3L, 2L, 2L, 3L, 2L, 3L, 1L, 3L, 3L, 3L, 2L, 3L, 3L, 3L, 
3L, 3L, 2L, 1L, 2L), levels = c("aaa", "bbb", 
"ccc"), class = c("ordered", "factor"))

df2 <-
structure(c(1L, NA, 3L, 1L, 1L, 3L, 2L, 1L, 3L, 2L, 2L, 3L, 1L, 
1L, 2L, 3L, 1L, 3L, 2L, 2L, 1L, 3L, 2L, 3L, 2L, 2L, 2L, 3L, 3L, 
1L, 2L, 1L, 3L, 2L, 3L, 1L, 2L, 3L, 2L, 3L, 2L, 1L, 3L, 3L, 3L, 
2L, 2L, 1L, 3L, 2L, 1L, 2L, 3L, 2L, 2L, 3L, 2L, 2L, 3L, 2L, 3L, 
1L, 2L, 2L, 1L, 2L, 1L, 1L, 2L, 3L, 3L, 3L, 1L, 2L, 1L, 2L, 2L, 
3L, 3L, 1L, 3L, 3L), levels = c("aaa", "bbb", 
"ccc"), class = c("ordered", "factor"))

df3 <- 
structure(c(3L, 2L, 2L, 3L, 3L, 2L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 
2L, 3L, 2L, 3L, 3L, 2L, 2L, 2L, 2L, 3L, 2L, 2L, 3L, 3L, 2L, 2L, 
3L, 1L, 3L, 2L, 2L, 3L, 3L, 3L, 2L, 3L, 2L, 3L, 2L, 3L, 2L, 3L, 
1L, 3L, 3L, 3L, 2L, 3L, 3L, 3L, 3L, 3L, 2L, 2L, 2L, 3L, 3L, 3L, 
3L, 2L, 3L, 3L, 3L, 3L, 3L, 2L, 2L, 2L, 2L, 3L, 3L, 3L, 3L, 3L, 
3L, 3L, 2L, 3L, 3L), levels = c("ddd", "eee", "fff"
), class = c("ordered", "factor"))

dftest1 <- 
structure(c(NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, 
NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, 
NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, 
NA, NA, NA, NA, 1L, NA, NA, NA, 1L, NA, NA, NA, 2L, NA, NA, NA, 
1L, NA, NA, NA, NA, NA, NA, 1L, NA, NA, NA, NA, NA, NA, NA, NA, 
NA, NA, 1L, NA, 2L), levels = c("AAA", "BBB"
), class = "factor")

dftest2 <-
structure(c(NA, NA, NA, NA, NA, NA, NA, 1L, NA, NA, NA, 1L, NA, 
1L, NA, 1L, NA, NA, NA, NA, NA, NA, NA, NA, 1L, NA, NA, NA, NA, 
NA, NA, 1L, 1L, NA, 1L, NA, NA, NA, NA, NA, NA, NA, NA, NA, 1L, 
NA, NA, NA, NA, 1L, NA, NA, NA, 1L, NA, 1L, NA, 1L, NA, NA, NA, 
1L, NA, NA, NA, NA, NA, NA, 1L, NA, NA, NA, NA, NA, NA, NA, NA, 
NA, NA, 1L, 1L, 1L), levels = "CCC", class = "factor")

我想将df1 、 df2和df3 （在我的例子中是因素）放在一起作为占位符vars2use ，可以这么说。

var2use <- c(var1, var2, var3)

然后应将该占位符与其他因素（ dftest1 、 dftest2 ）组合成一个数据集。

此实现按预期工作：

df <- data.frame(dftest1, dftest2, df1, df2, df3)

我希望它也可以以这种形式实现：

df <- data.frame(dftest1, dftest2, var2use)

但我得到一个错误：

Error in data.frame(dftest1, dftest2, var2use): 
arguments imply differing number of rows: 82, 3

背景是我想在不同的地方使用这种类型的占位符。 有谁知道如何解决这个问题？

Answer 1

更直接的方法是将您的值放入一个单独的 data.frame 中，然后在需要时cbind()这些值。 例如

vars2use <- data.frame(df1, df2, df3)
df <- cbind(data.frame(dftest1, dftest2), vars2use)
# df <- data.frame(dftest1, dftest2) |> cbind(vars2use) # alternative syntax

如果由于某种原因这些名称确实需要是字符向量，则可以在使用cbind之前使用mget()获取值

varnames <- c("df1", "df2", "df3")
df <- cbind(data.frame(dftest1, dftest2), mget(varnames))