From m@ech|er @end|ng |rom @t@t@m@th@ethz@ch  Mon Feb 18 18:12:59 2019
From: m@ech|er @end|ng |rom @t@t@m@th@ethz@ch (Martin Maechler)
Date: Mon, 18 Feb 2019 18:12:59 +0100
Subject: [Rd] Extract.data.frame.Rd about $.data.frame
In-Reply-To: <123537925.1052826.1550507821051@mail.yahoo.com>
References: <123537925.1052826.1550507821051.ref@mail.yahoo.com>
 <123537925.1052826.1550507821051@mail.yahoo.com>
Message-ID: <23658.59291.646340.17054@stat.math.ethz.ch>

>>>>> Suharto Anggono Suharto Anggono via R-devel 
>>>>>     on Mon, 18 Feb 2019 16:37:01 +0000 writes:

    > The statement in R devel: There is no \code{data.frame}
    > method for \code{$}, so \code{x$name} uses the default
    > method which treats \code{x} as a list (with no partial
    > matching of column names).  The replacement method (for
    > \code{$}) checks \code{value} for the correct number of
    > rows, and replicates it if necessary.

    > The added "(with no partial matching of column names)" is
    > wrong. The default method of '$' (for extraction) allows
    > partial matching for list; partial matching gives warning
    > if option warnPartialMatchDollar is TRUE.

Yes, thank you!
Indeed, of course it *is* matched when it can be matched uniquely;
otherwise it's silently not matched, returning NULL;
all as it has always been and well documented in ?Extract.

Martin

    > --------------------------------------------
    > On Fri, 15/2/19, Martin Maechler
    > <maechler at stat.math.ethz.ch> wrote:

    >  Subject: Re: [Rd] Extract.data.frame.Rd about
    > $.data.frame

    >  Cc: r-devel at r-project.org Date: Friday, 15 February,
    > 2019, 4:15 PM
 
>>>>> Suharto Anggono Suharto Anggono via R-devel

>>>>>    on Sun, 10 Feb 2019 16:33:25 +0000 writes:

    >> In R devel, data.frame method of '$' has been removed,
    >> but this part of "Details" section of
    >> Extract.data.frame.Rd still implies existence of the
    >> method.  The \code{data.frame} method for \code{$},
    >> treats \code{x} as a list, except that (as of R-3.1.0)
    >> partial matching of \code{name} to the names of \code{x}
    >> will generate a warning; this may become an error in
    >> future versions.  The replacement method checks
    >> \code{value} for the correct number of rows, and
    >> replicates it if necessary.


    >> Statement from before R 3.1.0 could be used again:

    >> There is no \code{data.frame} method for \code{$}, so
    >> \code{x$name} uses the default method which treats
    >> \code{x} as a list.  There is a replacement method which
    >> checks \code{value} for the correct number of rows, and
    >> replicates it if necessary.


    > [[elided Yahoo spam]] I've added a 2 x 2 words of
    > explanation to make it easier to understand.

    > Now changed.  Martin

    > ______________________________________________
    > R-devel at r-project.org mailing list
    > https://stat.ethz.ch/mailman/listinfo/r-devel



[Rd] Extract.data.frame.Rd about $.data.frame
Martin Maechler