as.data.frame is a _converter_, while data.frame is a _constructor_. Changing
the object contents is not what a conversion is for.
On October 28, 2023 11:39:22 AM PDT, Boris Steipe <boris.steipe at
utoronto.ca> wrote:>Thanks Duncan and Avi!
>
>That you could use NULL in a matrix() dimnames = list(...) argument
wasn't clear to me. I thought that would be equivalent to a one-element list
- and thereby define rownames. So that's good to know.
>
>The documentation could be more explicit - but it is probably more work to
do that than just patch the code to honour a col.names argument. (At least I
can't see a reason not to.)
>
>Thanks again!
>:-)
>
>
>
>
>> On Oct 28, 2023, at 14:24, avi.e.gross at gmail.com wrote:
>>
>> ?????,
>>
>> Try this where you tell matrix the column names you want:
>>
>> nouns <- as.data.frame(
>> matrix(c(
>> "gaggle",
>> "geese",
>>
>> "dule",
>> "doves",
>>
>> "wake",
>> "vultures"
>> ),
>> ncol = 2,
>> byrow = TRUE,
>> dimnames=list(NULL, c("collective", "category"))))
>>
>> Result:
>>
>>> nouns
>> collective category
>> 1 gaggle geese
>> 2 dule doves
>> 3 wake vultures
>>
>>
>> The above simply names the columns earlier when creating the matrix.
>>
>> There are other ways and the way you tried LOOKS like it should work
but
>> fails for me with a message about it weirdly expecting three rows
versus two
>> which seems to confuse rows and columns. My version of R is recent and
I
>> wonder if there is a bug here.
>>
>> Consider whether you really need the data.frame created in a single
>> statement or can you change the column names next as in:
>>
>>
>>> nouns
>> V1 V2
>> 1 gaggle geese
>> 2 dule doves
>> 3 wake vultures
>>> colnames(nouns)
>> [1] "V1" "V2"
>>> colnames(nouns) <- c("collective",
"category")
>>> nouns
>> collective category
>> 1 gaggle geese
>> 2 dule doves
>> 3 wake vultures
>>
>> Is there a known bug here or is the documentation wrong?
>>
>> -----Original Message-----
>> From: R-help <r-help-bounces at r-project.org> On Behalf Of Boris
Steipe
>> Sent: Saturday, October 28, 2023 1:54 PM
>> To: R. Mailing List <r-help at r-project.org>
>> Subject: [R] col.names in as.data.frame() ?
>>
>> I have been trying to create a data frame from some structured text in
a
>> single expression. Reprex:
>>
>> nouns <- as.data.frame(
>> matrix(c(
>> "gaggle",
>> "geese",
>>
>> "dule",
>> "doves",
>>
>> "wake",
>> "vultures"
>> ), ncol = 2, byrow = TRUE),
>> col.names = c("collective", "category")
>> )
>>
>> But ... :
>>
>>> str(nouns)
>> 'data.frame': 3 obs. of 2 variables:
>> $ V1: chr "gaggle" "dule" "wake"
>> $ V2: chr "geese" "doves" "vultures"
>>
>> i.e. the col.names argument does nothing. From my reading of
?as.data.frame,
>> my example should have worked.
>>
>> I know how to get the required result with colnames(), but I would like
to
>> understand why the idiom as written didn't work, and how I could
have known
>> that from the help file.
>>
>>
>> Thanks!
>> Boris
>>
>> ______________________________________________
>> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>>
>
>______________________________________________
>R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
>https://stat.ethz.ch/mailman/listinfo/r-help
>PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
>and provide commented, minimal, self-contained, reproducible code.
--
Sent from my phone. Please excuse my brevity.