Hi
In general the appearance of complex numbner is not a "problem", often they are linked to dissipation elements, but could also come from the way one needs solving the equations.
Applications not needing complex number are generally easier to handle, that is also why the use of complex number "feature" is generally turned "off" in the solvers parameters. When complex numbers appear, and the application mode does not expect them and has not already changed this default setting, then I agree the user must either turn them on, or reformulate his equation system. But in both cases it's better to exactly understand what you are demanding and how COMSOL issolving the case.
Now, I agree this is the theory and easy to say, I must admit that in your case I hanv't found an obvious clue, apart perhaps that COMSOL cannot always understand the boolean tests as "real case" selection of possible "complex" solutions. Therefre, I would suggest to try the empiicl way, turn on complex values and check carefully the reasults, the latter is anyhow mandatory especially when you start studies in new domains or new cases
Good luck
Ivar
In general the appearance of complex numbner is not a "problem", often they are linked to dissipation elements, but could also come from the way one needs solving the equations.
Applications not needing complex number are generally easier to handle, that is also why the use of complex number "feature" is generally turned "off" in the solvers parameters. When complex numbers appear, and the application mode does not expect them and has not already changed this default setting, then I agree the user must either turn them on, or reformulate his equation system. But in both cases it's better to exactly understand what you are demanding and how COMSOL issolving the case.
Now, I agree this is the theory and easy to say, I must admit that in your case I hanv't found an obvious clue, apart perhaps that COMSOL cannot always understand the boolean tests as "real case" selection of possible "complex" solutions. Therefre, I would suggest to try the empiicl way, turn on complex values and check carefully the reasults, the latter is anyhow mandatory especially when you start studies in new domains or new cases
Good luck
Ivar
