MathOverflow is a question and answer site for professional mathematicians. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top


I have two question about solving an elliptic equation using multigrids.

First, in case of Neumann boundary conditions : Does the error equation, which is solved on the coarse grid, have the same boundary condition than the solution on the fine grid ? In the case of Dirichlet BC, since the value of the solution is known at the boundary exactly, the error is zero there, so I suppose the error equation for dirichlet BC always have homogeneous dirichlet BC (right ?) but what about neumann BCs ?

Second, what happens at the restriction/interpolation steps when I have a non constant coefficient in my differential operator ? Exemple : F(x) - n(xh)*d2F(x)/dx2 = S(x). Is the function n(x) restricted/interpolated the same way the solution F is?



share|cite|improve this question

This is available on google books, and it has an example on page 113 using Neumann boundary conditions.

A multigrid tutorial

By William L. Briggs, Van Emden Henson, Stephen Fahrney McCormick

share|cite|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.