Set definition for matrix components

[ejanssen]

I'm trying to define each result of my matrix, i guess it isn't complicate but I didn't find anything about it.

[MJG · Accepted solution]

Two options:

[StuartBruff]

If you just want to sum the diagonal, then one way of doing it is to extract the diagonal and sum it

Alternatively, you could simply take the trace:

Stuart