On 07/15/2013 11:57 PM, Jed Brown wrote:
It's not a factor of 2, it's a factor of k where k is the size of the
subspace. Classical Gram-Schmidt needs one reduction per iteration
(normalization can be hidden), but modified needs k reductions.
Dear Jed,
Could you please explain a bit more on what you mean by
+ reduction
+ normalization can be hidden
On a problem that I am working on, cgs and mgs have a subtle difference.
I would like to learn more about these details.
More specifically, I would like to A orthonormalize a block of vectors,
say for a block size of 4, however I can not form A explicitly because
then it becomes large and dense. But it can be formed by a matrix vector
operation. Due this reason, cgs and mgs is a little different for me,
this is the source of the discussion.
Best,
Umut
