Re: [R] rownames, colnames, and date and time

From: Brandt, T. (Tobias) <>
Date: Mon 03 Jul 2006 - 18:28:58 EST

Hi all

I was wondering whether there has ever been an update on the rownames and colnames behaviour as described by Eric below?

I still get the same behaviour, exactly as described by Eric, on my WinXP installation of R-2.3.0. I also posted a message to r-help on Friday but looking through the online archives it seems to have not made it to the list. I would agree with Eric that a consistent use of the typecast would be a reasonable solution.

Any comments?

Tobias Brandt
Quantitative Analyst
Taquanta Asset Managers
Nedbank Clock Tower
Victoria & Alfred Waterfront, Cape Town 8001 Tel : +27 (0) 21 416 6602
Fax : +27 (0) 21 416 9945
Email : <>

>-----Original Message-----
>[] On Behalf Of Erich Neuwirth
>Sent: 21 March 2006 01:31 PM
>Cc: Christian Prinoth
>Subject: [R] rownames, colnames, and date and time
>I noticed something surprising (in R 2.2.1 on WinXP) According
>to the documentation, rownames and colnames are character vectors.
>Assigning a vector of class POSIXct or POSIXlt as rownames or
>colnames therefore is not strictly according to the rules.
>In some cases, R performs a reasonable typecast, but in some
>other cases where the same typecast also would be possible, it
>does not.
>Assigning a vector of class POSIXct to the rownames or names
>of a dataframe creates a reasonable string representation of
>the dates (and possibly times).
>Assigning such a vector to the rownames or colnames of a
>matrix produces rownames or colnames consisting of the integer
>representation of the date-time value.
>Trying to assign a vector of class POSIXlt in all cases
>(dataframes and matrices, rownames, colnames, names) produces an error.
>Demonstration code is given below.
>This is somewhat inconsistent.
>Perhaps a reasonable solution could be that the typecast used
>for POSIXct and dataframes is used in all the other cases also.
># the following lines will not work and
># produce errors
>Erich Neuwirth
>Institute for Scientific Computing and
>Didactic Center for Computer Science
>University of Vienna
>phone: +43-1-4277-39464 fax: +43-1-4277-39459
> mailing list
>PLEASE do read the posting guide!

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        [[alternative HTML version deleted]] mailing list PLEASE do read the posting guide! Received on Mon Jul 03 18:32:02 2006

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