wolffd@0: p1 = log(1e-5);
wolffd@0: p2 = log(5*1e-6);
wolffd@0: p3 = log(sum(exp([p1 p2])))
wolffd@0: p4 = logsumexp([p1 p2],2)
wolffd@0: p5 = logsum([p1 p2])
wolffd@0: p6 = logsum([p1 p2])