Hello. I want to multiply a banded matrix d_a (width=height=Ns) with a part of a vector d_x (size=Ns*Ns).
Suppose I want to multiply d_a with a part of d_x starting from the 10th element of it. The following code doesn’t work.
where kl=ku=2, al=1, bet=0.
There are two explanations: 1)Either it is wrong or, 2) Multiplying a Matrix with a part of a vector doesn’t work
Which of the two is happening?