Yes, obviously, with hindsight. In lieu of code change, the colnames
documentation could indicate the restricted sense of 'equivalent'.
For a data frame, 'rownames' and 'colnames' are equivalent to
'row.names' and 'names' respectively.
It might help to add 'names' to See Also of ?data.fr
On Wed, 27 Sep 2006, Martin Morgan wrote:
> colnames on a data.frame with implicit row.names
>
>> df <- data.frame(x=1:600)
>
> is slow
>
>> system.time(colnames(df))
> [1] 21.655 0.327 21.987 0.000 0.000
>> system.time(names(df))
> [1] 0 0 0 0 0
>
> because colnames calls dimnames calls ro
colnames on a data.frame with implicit row.names
> df <- data.frame(x=1:600)
is slow
> system.time(colnames(df))
[1] 21.655 0.327 21.987 0.000 0.000
> system.time(names(df))
[1] 0 0 0 0 0
because colnames calls dimnames calls row.names.data.frame calls
as.character on the implicit row.na
