Copyright © 2010 Yang Shang-jun et al. This is an open access article distributed under the
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In the previous paper by the first and the third authors, we present six algorithms for determining
whether a given symmetric matrix is strictly copositive, copositive (but not strictly), or not copositive.
The algorithms for matrices of order are not guaranteed to produce an answer. It also shows that
for 1000 symmetric random matrices of order 8, 9, and 10 with unit diagonal and with positive entries all
being less than or equal to 1 and negative entries all being greater than or equal to , there are 8, 6, and 2 matrices remaing undetermined, respectively. In this paper we give two more algorithms for and our experiment shows that no such matrix of order 8 or 9 remains undetermined; and almost always no
such matrix of order 10 remains undetermined. We also do some discussion based on our experimental