Allin Cottrell schrieb:
On Fri, 27 Nov 2009, Sven Schreiber wrote:
> ok() also supports lists, while missing() doesn't, is this deliberate?
For ok() with a list argument the return value is unambiguous:
it's a series with 1s for observations where no values are
missing, 0s otherwise. With missing() it's not so clear what it
should return if given a list: 1s for all missing, or for any
missing?
Well, missing() seems to be designed as being in some sense the negation
of ok(). So that would mean missing() is equivalent to "not ok()"; in
this list context missing() would be 1 for *any* missing value in a
variable. Personally this strikes me as quite intuitive and also
practical -- I mean when would you ever be really interested if a series
had *all* n of its values missing, as opposed to, say, "only" n-1 missings?
But I can easily live without it, I was mainly wondering whether this
was just an oversight.
cheers,
sven