matStig
(Package: expm) :
Stig's "infamous" Example Matrix
Stig Mortensen wrote on Oct 22, 2007 to the authors of the Matrix package with subject “Strange result from expm”. There, he presented the following 8 * 8 matrix for which the Matrix expm() gave a “strange” result. As we later researched, the result indeed was wrong: the correct entries were wrongly permuted. The reason has been in the underlying source code in Octave from which it had been ported to Matrix.