Message-ID: <1319348682073-3929739.post@n4.nabble.com>
Date: 2011-10-23T05:44:42Z
From: statfan
Subject: symmetric matrix multiplication
I have a symmetric matrix B (17x17), and a (17x17) square matrix A. If do
the following matrix multiplication I SHOULD get a symmetric matrix, however
i don't. The computation required is:
C = t(A)%*%B%*%A
here are some checks for symmetry
> (max(abs(B - t(B))))
[1] 0
> C = t(A)%*%B%*%A
> (max(abs(C - t(C))))
[1] 3.552714e-15
Any help on the matter would be very much appreciated.
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