[Trilinos-Users] Epetra - Dense Matrix-Vector multiply basics

[Gyorgy Matyasfalvi]

Dear Developers/Users:

I have a question concerning matrix-vector multiplies:

1) Is there a document or example file that explains the basics of
matrix-vector multiplies? Preferably isolated examples of mtx-vec mults.
instead of being embedded in some algorithm.

If this doesn't exist. Then I'd be interested in finding out:

2) How to do dense matrix, dense vector multiplies?
I assume it's done via the Epetra_MultiVector class. However, the only
operation that seems to have an effect is the following:

y = A x
using
y.Multiply('N', 'N', 1.0, A, x, 0.0)
(x was constructed using an Epetra_LocalMap
A, and y were constructed using the same Epetra_Map)

The problem is that if I want to compute for example:

x = y^T A
using
x.Multiply('T', 'N', 1.0, y, A, 0.0)

it seems the Multiply() operation doesn't do anything x remains unchanged.

What am I doing incorrectly here?
Thanks a lot! Best,
Gyorgy
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