I am trying to mess with example code, but when I copy and paste into the online compiler it throws an error. It doesn’t like Line 40
int k = EigenValue(OP, B, sym=true, sigma=sigma, value=ev, vector=eV,
tol=1e-10, maxit=0, ncv=0);
Everything runs up until that point. The example is Eigenfucntion of the shifted laplacian on the square. Any ideas what is going on?