From Bill.Venables at csiro.au  Sat Feb 11 02:46:33 2006
From: Bill.Venables at csiro.au (Bill.Venables@csiro.au)
Date: Sat, 11 Feb 2006 12:46:33 +1100
Subject: [Rd] Arguments of 'transform'
Message-ID: <B998A44C8986644EA8029CFE6396A924546AF5@exqld2-bne.qld.csiro.au>

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'. ***

Just another little seed.

Bill.

Bill Venables, 
CMIS, CSIRO Laboratories, 
PO Box 120, Cleveland, Qld. 4163 
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[Rd] Arguments of 'transform'
Bill.Venables@csiro.au