R: Dimension names in tables and multi-dimensional arrays

Question

Since a function that I use requires a table object as parameter, I would like to convert a multidimensional array to a table, but I have problems with dimension names. As specified in the help file of `as.table`, the `dnn` parameter should contain dimnames names. ``` dnn … the names to be given to the dimensions in the result (the dimnames names). ``` But even when specifying `dnn`, my tables produced by `as.table` have no dimension names. The following code illustrates my problem. ``` >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 ``` now try the same when constructing the table from an array: ``` >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 #…

Accepted Answer

`as.table` doesn't have a `dnn` argument. You need to set the dimnames manually.

```
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
```

R: Dimension names in tables and multi-dimensional arrays

Solution

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