On Sat, 2006-01-21 at 14:07 -0500, Duncan Murdoch wrote:
> On 1/21/2006 1:21 PM, Gavin Simpson wrote:
> > On Sat, 2006-01-21 at 13:12 -0500, Gabor Grothendieck wrote:
> >> This was discussed just recently. This is a design
> >> error but the maintainers claim there are no cases of
> >> interest where it matters.
> >
> > Thanks Gabor,
> >
> > I must have missed that discussion whilst I was on vacation. If what you
> > say was the outcome of that discussion, it still means that the
> > documentation for xy.coords is in error, as you may *not* provide a
> > single argument 'x'.
>
> You need to read the whole page. You provide a single argument x by
> setting y to NULL, not by leaving it missing (as the docs said in
> earlier versions).
>
> If you want to submit a patch to the docs, I'll take a look, but I don't
> like the one below. It has basically the same flaw as the current docs:
> you're providing two objects, not a single object. Probably the
> clearest thing to do is just to say "see below" after the current
> wording, to point out that there are funny conventions here.
How about:
x, y: the x and y coordinates of a set of points. Alternatively, 'x' may
be a formula, list, time series or a matrix-like object with two
columns, in which case 'y' should be 'NULL', see Details below.
Or,
x, y: the x and y coordinates of a set of points. Alternatively, 'x' may
take different forms. If so, 'y' must be supplied as 'NULL'. See Details
below.
Or,
x, y: the x and y coordinates of a set of points. Alternatively, 'x' may
take different forms. See Details below.
I can provide you with a revised Rd file for xy.coords() if you think
any of the above are acceptable
All the best,
Gav
>
> > If the intention is to keep the current behaviour - which is fine - then
> > the documentation should be changed, perhaps along the lines of:
> >
> > x, y: the x and y coordinates of a set of points. Alternatively, a
> > single object 'x' can be provided if 'y = NULL' is also
> > supplied.
> >
> > 'object' might not be correct here - is a formula an 'object'?
>
> Sure, why not?
>
> Duncan Murdoch
>
> >
> > Cheers,
> >
> > Gav
> >
> >> On 1/21/06, Gavin Simpson <[EMAIL PROTECTED]> wrote:
> >>> Hi,
> >>>
> >>> I noticed the following problem with xy.coords() in R 2.2.1-patched
> >>> (version info at the foot of this email) and R 2.3.0 unstable
> >>> (subversion no: r37123):
> >>>
> >>>> xy.coords(x = matrix(1:20, ncol = 2))
> >>> Error in xy.coords(x = matrix(1:20, ncol = 2)) :
> >>> argument "y" is missing, with no default
> >>>> xy.coords(x = matrix(1:20, ncol = 2), y = NULL)
> >>> $x
> >>> [1] 1 2 3 4 5 6 7 8 9 10
> >>>
> >>> $y
> >>> [1] 11 12 13 14 15 16 17 18 19 20
> >>>
> >>> $xlab
> >>> [1] "[,1]"
> >>>
> >>> $ylab
> >>> [1] "[,2]"
> >>>
> >>> And:
> >>>
> >>>> xy.coords(x = data.frame(x = 1:10, y = 1:10))
> >>> Error in xy.coords(x = data.frame(x = 1:10, y = 1:10)) :
> >>> argument "y" is missing, with no default
> >>>> xy.coords(x = data.frame(x = 1:10, y = 1:10), y = NULL)
> >>> $x
> >>> [1] 1 2 3 4 5 6 7 8 9 10
> >>>
> >>> $y
> >>> [1] 1 2 3 4 5 6 7 8 9 10
> >>>
> >>> $xlab
> >>> [1] "x"
> >>>
> >>> $ylab
> >>> [1] "y"
> >>>
> >>> ... for example.
> >>>
> >>> ?xy.coords states:
> >>>
> >>> x, y: the x and y coordinates of a set of points. Alternatively, a
> >>> single argument 'x' can be provided.
> >>>
> >>> Given that, I would have thought the above examples would have worked
> >>> without explicitly passing y = NULL to xy.coords(). However, ?xy,coords
> >>> later states:
> >>>
> >>> If 'y' is 'NULL' and 'x' is a
> >>>
> >>> and the examples all illustrate the use of NULL passed as y.
> >>>
> >>> Is this a documentation error and a single argument x is not allowed, or
> >>> is this a bug in the code? Either way, ?xy.coords contradicts itself as
> >>> one would expect to be able to pass only x given the statement above.
> >>>
> >>> If this is a bug in the code, a potential workaround appears to be to
> >>> change the first line of xy.coords from:
> >>>
> >>> if (is.null(y)) {
> >>>
> >>> to
> >>>
> >>> if (missing(y) || is.null(y)) {
> >>>
> >>> but I haven't tested this on anything other than my two examples.
> >>>
> >>> I will file a bug report if my observation is correct - but given all
> >>> the erroneous bug reports lately, I thought I'd try my luck here where
> >>> an error on my part would not cause the maintainers of the bug tracker
> >>> any extra work.
> >>>
> >>>> version
> >>> _
> >>> platform i686-pc-linux-gnu
> >>> arch i686
> >>> os linux-gnu
> >>> system i686, linux-gnu
> >>> status Patched
> >>> major 2
> >>> minor 2.1
> >>> year 2006
> >>> month 01
> >>> day 18
> >>> svn rev 37123
> >>> language R
> >>>> sessionInfo()
> >>> R version 2.2.1, 2006-01-18, i686-pc-linux-gnu
> >>>
> >>> attached base packages:
> >>> [1] "methods" "stats" "graphics" "grDevices"
> >>> [5] "utils" "datasets" "base"
> >>>
> >>> All the best,
> >>>
> >>> Gav
> >>>
> >>> --
> >>> %~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%
> >>> Gavin Simpson [T] +44 (0)20 7679 5522
> >>> ENSIS Research Fellow [F] +44 (0)20 7679 7565
> >>> ENSIS Ltd. & ECRC [E] gavin.simpsonATNOSPAMucl.ac.uk
> >>> UCL Department of Geography [W] http://www.ucl.ac.uk/~ucfagls/cv/
> >>> 26 Bedford Way [W] http://www.ucl.ac.uk/~ucfagls/
> >>> London. WC1H 0AP.
> >>> %~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%
> >>>
> >>> ______________________________________________
> >>> R-devel@r-project.org mailing list
> >>> https://stat.ethz.ch/mailman/listinfo/r-devel
> >>>
>
--
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Gavin Simpson [T] +44 (0)20 7679 5522
ENSIS Research Fellow [F] +44 (0)20 7679 7565
ENSIS Ltd. & ECRC [E] gavin.simpsonATNOSPAMucl.ac.uk
UCL Department of Geography [W] http://www.ucl.ac.uk/~ucfagls/cv/
26 Bedford Way [W] http://www.ucl.ac.uk/~ucfagls/
London. WC1H 0AP.
%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%
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