Hello, all.
I have a list of 4 matrices, each is 4x4:
gg:[gam[0],gam[1],gam[2],gam[3]];
When I write some vector consisting of 4 elements:
aa:[a[0],a[1],a[2],a[3]];
the product
gg . aa;
gives me expected result: it is a[0]*gam[0] + ... + a[3]*gam[3], which
appears to be 4x4 matrix
Now if I have a list of 4 vectors,
dpsi_:[[d0psi0,d0psi1,d0psi2,d0psi3],
[d1psi0,d1psi1,d1psi2,d1psi3],[d2psi0,d2psi1,d2psi2,d2psi3],
[d3psi0,d3psi1,d3psi2,d3psi3]];
the product gg . dpsi_ gives me also 4x4 matrix, which is not what I expect.
I expect the reulst to be 4-vector, namely
gg[1] . dpsi_[1]+gg[2].dpsi_[2]+gg[3].dpsi_[3]+gg[4].dpsi_[4];
Can you please advise me how can I achieve the expected behaviour?
Thanks in advance,
Vadim.