From: John Pitney <john@pi...>  20050715 00:12:40

Hi, I'm fairly new to finite element methods (my background is mostly in experimental physics), and I'm trying to learn the basics with libMesh and a copy of Bathe. In reading the examples, I see exact_solution prototypes declared, and sometimes actual exact values and exact derivatives are attached. What role does the exact_solution play in solving a real problem? What if one were solving the problem in Example 14, but didn't already know the the exact solution, u(r,\theta)? Sorry to bug the list with such a beginner question! If the answer is too complicated for an email response, a pointer to a good reference would be great. Thanks to all the developers for an impressive system! Best regards, John Pitney 