17 Feb
2012
17 Feb
'12
9:44 a.m.
On Fri, Feb 17, 2012 at 06:54, Thomas Witkowski < [email protected]> wrote:
Maybe some related question: Most textbooks write that the compatibility condition to solve a system with constant null space is that the right hand side has zero mean value. Today I read part of the Multigrid-book written by Trottenberg, and there the condition is written in a different form (eq 5.6.22 on page 185): the integral of the right hand side must be equal on the whole domain and on the boundary. Does any of you have an explanation for this condition? Is there a book/paper that considers the compatibility condition in more details?
It's common to project the null space out of the right hand side (yielding a "consistent" right hand side).