help on what a code means or does

K(edof(1,:),edof(1,:)) = T1'*k1*T1;     % assemble k1 to global K

I found the above code and could not understand. What does it does?

[David Goodmanson]

Hi Daniel,

this is like trying to come up with the name of a tune after someone has played one note.

however, it looks like the right hand side is a similarity transformation of a matrix k1. Let's say that the right hand side is an m x m matrix, and K is a larger matrix that is n x n. And suppose edof is an m x m index matrix, so edof(1,:) is a vector of indices, of length m. Then this would write an m x m sub-block of right-hand-side values into K. Why that is a good thing to do is totally nebulous.

[Daniel Mehari]

Thanks David for your answer. It helped me a lot.

[Daniel Mehari]

I have also another quesion I would love if you can help me with. Thanks beforehand.