Collocation points for a global relation
= Collocation points for a global relation
{title2=$\lambda_{jn}$}
These are chosen complex values of a <spectral parameter for a linear boundary value problem> at which a truncated <global relation for a linear boundary value problem> is enforced. Their directions and magnitudes determine which boundary side and which tangential mode are tested. Suitable row combinations can give much better conditioning than arbitrary raw samples.