[S] aov and NAs

Christian Hoffmann (christian.hoffmann@wsl.ch)
Thu, 02 Jul 1998 10:05:14 +0200

Hi there,

For my application of manova, Y = X*B + U, I do not want to lose all the
rows of X where there are one or more NAs in them. As I can see from the
description of %*% (which, I suspect, is used to form X'X), NAs are
allowed in the factors, but the resulting sum will be NA.

Can aov be altered so that in the computation of X'X terms of NA*something
will be treated as zero?
Are there theoretical reasons against it?

In the worst case I would have to program aov myself to reflect the desired

Any help?

PS: This problem has to do with my earlier post:

>> (beta-hat-ij,beta-hat-kl) = sigma-jl*g-ik, with g the elements of G <-
>> (X'X)^(-1), where X is the design matrix. I have the feeling that G is
>> constructed inside method "aov", but somehow I cannot find it. I want to
>> make it appear as a result parameter $G.

Thank you

Christian W. Hoffmann
Swiss Federal Institute for Forest, Snow and Landscape Research
CH-8903 Birmensdorf, Switzerland
phone: ++41-1-739 22 77 fax : ++41-1-739 22 15 e-mail: hoffmann@wsl.ch
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