[Rd] Arguments of 'transform'

John Fox jfox at mcmaster.ca
Sat Feb 11 17:39:41 CET 2006


Dear Bill,

I didn't realize that "x." would be partially matched by "x" when there was
a first (unnamed) argument in the function call -- but I see the error now.

Thanks,
 John

--------------------------------
John Fox
Department of Sociology
McMaster University
Hamilton, Ontario
Canada L8S 4M4
905-525-9140x23604
http://socserv.mcmaster.ca/jfox 
-------------------------------- 

> -----Original Message-----
> From: r-devel-bounces at r-project.org 
> [mailto:r-devel-bounces at r-project.org] On Behalf Of 
> Bill.Venables at csiro.au
> Sent: Saturday, February 11, 2006 11:07 AM
> To: jfox at mcmaster.ca; p.dalgaard at biostat.ku.dk
> Cc: r-devel at stat.math.ethz.ch
> Subject: Re: [Rd] Arguments of 'transform'
> 
> Hi John,
> 
> Unfortunately I don't think that will fix it because of 
> partial matching.
> 
> (That would be OK if the argument sequence were reversed to:
> 
> 	function(..., x.)
> 
> since partial matching does not occur with arguments coming 
> after ..., but it would break ALL existing code.)
> 
> Bill.
> 
> -----Original Message-----
> From: John Fox [mailto:jfox at mcmaster.ca]
> Sent: Sunday, 12 February 2006 1:39 AM
> To: 'Peter Dalgaard'; Venables, Bill (CMIS, Cleveland)
> Cc: r-devel at stat.math.ethz.ch
> Subject: RE: [Rd] Arguments of 'transform'
> 
> 
> Dear Peter and Bill,
> 
> How about changing the current "x argument to something like 
> "x."? That
> should make the problem that Bill points out less likely and still be
> backwards compatible with using "x" in the call to transform().
> 
> Regards,
>  John
> 
> --------------------------------
> John Fox
> Department of Sociology
> McMaster University
> Hamilton, Ontario
> Canada L8S 4M4
> 905-525-9140x23604
> http://socserv.mcmaster.ca/jfox 
> -------------------------------- 
> 
> > -----Original Message-----
> > From: r-devel-bounces at r-project.org 
> > [mailto:r-devel-bounces at r-project.org] On Behalf Of Peter Dalgaard
> > Sent: Saturday, February 11, 2006 4:43 AM
> > To: Bill.Venables at csiro.au
> > Cc: r-devel at stat.math.ethz.ch; p.dalgaard at biostat.ku.dk
> > Subject: Re: [Rd] Arguments of 'transform'
> > 
> > <Bill.Venables at csiro.au> writes:
> > 
> > > If you would like a 10 second R puzzle, you might like to 
> > think about 
> > > this one:
> > > 
> > > 
> > > > g <- expand.grid(long = 130:140, lat = -(10:25)) gp <- 
> > transform(g, 
> > > > x = long, y = lat)
> > > Error in transform(g, x = long, y = lat) : 
> > >         object "long" not found
> > > 
> > > 
> > > I don't expect this hasn't come up before, but I can't find 
> > mention of 
> > > it.  I suggest that to minimise this little stumbling block for 
> > > beginners (and others) we either
> > > 
> > > 	change the name of the principal argument in transform from 'x'
> > > to, say '.x' (or even 'data' as it is in 'with' for example)  OR
> > > 
> > > 	at least put a note in the help file for 'transform' in 
> > the 'Detalis' 
> > > section to say
> > >      
> > > 	*** NOTE: The only tag name unavailable to be used is 'x'. ***
> > 
> > Yes it has come up before (surprisingly rarely though), and 
> > you're probably right although changing argument names of 
> > functions should never be taken lightly as there could be 
> > people using the current ones. 
> > 
> > > 
> > > Just another little seed.
> > 
> > ...which is connected to my grievances with attach() &c the 
> other day.
> > Something about transform() just isn't The Right Way.
> > 
> > -- 
> >    O__  ---- Peter Dalgaard             Øster Farimagsgade 5, Entr.B
> >   c/ /'_ --- Dept. of Biostatistics     PO Box 2099, 1014 Cph. K
> >  (*) \(*) -- University of Copenhagen   Denmark          Ph:  
> > (+45) 35327918
> > ~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk)                  FAX: 
> > (+45) 35327907
> > 
> > ______________________________________________
> > R-devel at r-project.org mailing list
> > https://stat.ethz.ch/mailman/listinfo/r-devel
> 
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