R：表和多维数组中的维度名称

Question

由于我使用的函数需要表对象作为参数，因此我想将多维数组转换为表，但维度名称有问题。

as.table 的帮助文件中指定，dnn 参数应包含 dimnames 名称。

dnn … the names to be given to the dimensions in the result (the dimnames names).

但即使指定dnn，我由as.table 生成的表也没有维度名称。

以下代码说明了我的问题。

>test <- table(c("a","b","c","c","c"),c("1","2","3","2","2"),dnn=c("letters","numbers"))
>test 

          numbers
letters 1 2 3
      a 1 0 0
      b 0 1 0
      c 0 2 1

# this works perfectly

现在在从数组构造表时尝试同样的方法：

>my2dimdata <- array(c(1,0,0,0,1,2,0,0,1),dim=c(3,3),
                    dimnames=list(c("a","b","c"),
                                  c("1","2","3")))
>my2dimdata

  1 2 3
a 1 0 0
b 0 1 0
c 0 2 1

# the array as expected

>my2dimtable <- as.table(my2dimdata,dnn=c("letters","numbers"))
>my2dimtable

  1 2 3
a 1 0 0
b 0 1 0
c 0 2 1

# there are no dimnames

Answer 1

as.table 没有 dnn 参数。您需要手动设置暗名。

my2dimdata <- array(c(1,0,0,0,1,2,0,0,1),dim=c(3,3),
                    dimnames=list(c("a","b","c"),
                                  c("1","2","3")))

my2dimdata <- as.table(my2dimdata)
names(attributes(my2dimdata)$dimnames) <- c("letters","numbers")

#        numbers
# letters 1 2 3
#       a 1 0 0
#       b 0 1 0
#       c 0 2 1