This is a follow-up to my previous post. Classical Gram-Schmidt and Modified Gram-Schmidt are two algorithms for orthogonalizing a set of vectors. Householder elementary reflectors can be used for the same task. The three algorithms have very different roundoff error properties.... 更多内容 >>

Magic Stars are a little like Magic Squares. My grandson was introduced to them in his junior high school math class.... 更多内容 >>

I have just returned from the huge Supercomputing 2012 conference in Salt Lake City. I can report on interesting reactions to some questions I posed in last week's blog and on some impressive speedup results when we ran the code in last week's blog on a parallel cluster in the Cloud.... 更多内容 >>