Re: Another Question re Golub

In article
<f726d7c1-1938-413d-a841-283aade658c6@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>,
Ken <ken.allen@xxxxxxxxxxxxx> wrote:

Oops, I meant partition. But that's the point. AQ only has p
columns. There aren't any columns left over for A2. Similarly, Q^Tx
only has p rows.

not so:
B is p x n if B^T is n x p

Q^TB^T= | R | p -> Q^TB^T is n x p. since R is square.
| 0 | n-p

therefore Q^T is n x n as is Q
AQ is m x n
Q^Tx is n x 1
.