[Rd] is.vector(as.vector(x, m), m) not always TRUE

peter dalgaard pdalgd at gmail.com
Wed Apr 24 08:11:08 CEST 2013

On Apr 24, 2013, at 01:48 , Hervé Pagès wrote:

> In the man page for as.vector() (same as man page for vector()):
>     Writers of methods for ‘as.vector’ need to take care to follow the
>     conventions of the default method.  In particular
>        • Argument ‘mode’ can be ‘"any"’, any of the atomic modes,
>          ‘"list"’, ‘"expression"’, ‘"symbol"’, ‘"pairlist"’ or one of
>          the aliases ‘"double"’ and ‘"name"’.
>        • The return value should be of the appropriate mode.  For
>          ‘mode = "any"’ this means an atomic vector or list.
>        • Attributes should be treated appropriately: in particular
>          when the result is an atomic vector there should be no
>          attributes, not even names.
>        • ‘is.vector(as.vector(x, m), m)’ should be true for any mode
>          ‘m’, including the default ‘"any"’.
> But:
>  > is.vector(as.vector("a", "name"), "name")
>  [1] FALSE
> Mmmh, the default method itself doesn't seem to follow its own
> conventions :-/

Looks like there should be a straightforward fix, since

> is.vector(as.vector("a", "name"), "symbol")
[1] TRUE

so it is just a matter of implementing "name" as synomyous with "symbol".

Peter Dalgaard, Professor,
Center for Statistics, Copenhagen Business School
Solbjerg Plads 3, 2000 Frederiksberg, Denmark
Phone: (+45)38153501
Email: pd.mes at cbs.dk  Priv: PDalgd at gmail.com

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