[ From a message by David Krantz ]
> > A method that will work, on a matrix denoted y, is
> >
> > y[(((y > 0) - 1) %*% rep(1, ncol(y))) == 0, ].
> >
> > Perhaps someone else will come up with an easier way.
>
> I think that
>
> y[apply(y>0,1,all),]
>
> is sexier, if not easier.
My (privately emailed) solution was
A[apply(A, 1, function(x) all(x >= 0)), ]
which has the advantage (by design) of not needing to create a matrix-sized
intermediate result like y > 0. (The original question was very vague;
is 0 positive? it could have meant any or all, ...)
As to how to find out: read some good books on S programming and study the
examples. Two of the four S programming books on my shelf had examples of
all() and apply() ....
-- Brian D. Ripley, ripley@stats.ox.ac.uk Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272860 (secr) Oxford OX1 3TG, UK Fax: +44 1865 272595 ----------------------------------------------------------------------- This message was distributed by s-news@wubios.wustl.edu. To unsubscribe send e-mail to s-news-request@wubios.wustl.edu with the BODY of the message: unsubscribe s-news