Thanks everyone. Obvious when you think about it, and you check that both the matrices your trying it with are actually matrices... instead of one being a list.
On Wed, 2006-15-03 at 06:03 -0500, tom wright wrote: > Can someone please give me a pointer here. > I have two matrices > > matA > A B C > 1 5 2 4 > 2 2 4 3 > 3 1 2 4 > > matB > A B C > 1 TRUE FALSE TRUE > 2 FALSE TRUE TRUE > 3 FALSE FALSE FALSE > > how do I extract all the values from matA where the coresponding entry > in matB == TRUE (or FALSE), perferably in vector form. > > Many thanks > tom > > ______________________________________________ > R-help@stat.math.ethz.ch mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html > ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html