[Rd] all.equal() improvements (PR#8191)

[Martin Maechler]

>>>>> "BDR" == Prof Brian Ripley <ripley at stats.ox.ac.uk>
>>>>>     on Mon, 2 Jan 2006 20:39:18 +0000 (GMT) writes:

    BDR> Martin,
    BDR> I have some tests running over CRAN now (RUnit has also failed), 

thank you, Brian, for the feedback

    BDR> but have  already noticed things like

    >> swiss[, 1] -> x
    >> names(x) <- rownames(swiss)
    >> all.equal(x, x[1:10])
    BDR> [1] "Names: Lengths (47, 10) differ (string compare on first 10)"
    BDR> [2] "Numeric: lengths (47, 10) differ"

    BDR> which is telling me the obvious, with the result that the reports from 
    BDR> e.g. rpart are cluttered to the detriment of legibility.

    BDR> I think we need to think harder about what should be reported when the
    BDR> objects differ in mode or length.

I agree;  the above is good example.
[OTOH, I don't think the above behavior to be a complete show
 stopper; since it's somewhat close to the way S-plus does things]

    BDR> Brian

    BDR> On Mon, 2 Jan 2006 maechler at stat.math.ethz.ch wrote:

    >> I'm "happy" to have found the first problem myself:
    >> 
    >> 'Matrix' doesn't pass R CMD check  anymore with the change I had
    >> committed:

    BDR> I am seeing a problem in setGeneric which stops it being installed.

{ah yes;  for R-devel you need the "next" version of Matrix
 the important part of which I'll commit shortly to R-packages;  it
 will take another day before I'll upload it to CRAN}


    >> Basically because of this:
    >> 
    >> > all.equal(cbind(1:5), matrix(1:5, 5,1, dimnames=list(NULL,NULL)))
    >> [1] "Attributes: < Names: Lengths (1, 2) differ (string compare on first 1) >"
    >> [2] "Attributes: < Length mismatch: comparison on first 1 components >"
    >> 
    >> This new behavior is "S-compatible" insofar as S-plus 6.1 also
    >> returns non-TRUE.
    >> 
    >> Is this what we want?
    >> {we'll see soon how many other CRAN packages are having problems for it}
    >> 
    >> In my intuition, I'd have liked all.equal()  to return TRUE for the above,
    >> since in principle,  dimnames = NULL  or dimnames = list(NULL,NULL)
    >> is a trivial difference.
    >> OTOH, it will need "special case" code to assure this, and I
    >> wonder if that's worth it.
    >> 
    >> Please comment!
    >> Martin
    >> 
    >>>>>>> "MM" == Martin Maechler <maechler at stat.math.ethz.ch>
    >>>>>>> on Mon,  2 Jan 2006 18:00:15 +0100 (CET) writes:
    >> 
    MM> I've now finally finalized my work on a subset of Andy's
    MM> propositions, and committed it to R-devel.
    >> 
    MM> The current change doesn't show in our own checks and
    MM> examples, but may well in other people's package checks.
    MM> For this reason, I've also added a line to the
    MM> 'USER-VISIBLE CHANGES' part of the NEWS file.

    BDR> -- 
    BDR> Brian D. Ripley,                  ripley at stats.ox.ac.uk
    BDR> Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
    BDR> University of Oxford,             Tel:  +44 1865 272861 (self)
    BDR> 1 South Parks Road,                     +44 1865 272866 (PA)
    BDR> Oxford OX1 3TG, UK                Fax:  +44 1865 272595