Supported Linear Algebra Operations?

[klausbu]

I am thinking on implementing stronger, parallel preconditioners for "p".

Is there support for the following linear algebra operations:

1: general matrix x matrix multiplication
2: matrix x diagonal matrix multiplication where the diagonal value becomes the multiplication factor of its row or column depending on whether it's pre- or post multiplied - this might be implemented in a simpler way than the general matrix x matrix multiplication
3: subtraction of a matrix C from the identity matrix I i.e. M_temp = I - C
4: invert the diagonal D i.e. matrix Dinv_temp = 1.0/D
5: adding/subtracting matrices i.e. matrix J = M_temp +/- N_temp

[klausbu]

1: general matrix x matrix multiplication >> not needed, there's a trick to avoid it
2: matrix (just lower will do) x diagonal matrix multiplication where the diagonal value becomes the multiplication factor of its row or column depending on whether it's pre- or post multiplied - this might be implemented in a simpler way than the general matrix x matrix multiplication
3: subtraction of a matrix C from the identity matrix I i.e. M_temp = I - C >> there is probably a workaround
4: invert the diagonal D i.e. matrix Dinv_temp = 1.0/D >> this is available, I found it when studying the source code
5: adding/subtracting matrices i.e. matrix J = M_temp +/- N_temp

2. and 5. are open questions, 5. will probably also cover 3.