Hello,

How do you modify only the main diagonal of a matrix? I can see functions for extracting the main diagonal but is there a way to do this by just adding a small number to it. I am trying to add some Tikohnov Regularisation to my matrix.

Thanks.

For scalar to vector addition, move to the array world, e.g.:

Code: Select all

MatrixXd mat;
// ...
mat.diagonal().array() += 1.2345;