25 January 2013 02:22:12 PM FEM2D_POISSON_SPARSE: C++ version: Compiled on Jan 25 2013 at 14:14:03. A version of FEM2D_POISSON using sparse storage and an iterative solver. Solution of the Poisson equation in an arbitrary region in 2 dimensions. - DEL H(x,y) DEL U(x,y) + K(x,y) * U(x,y) = F(x,y) in the region U(x,y) = G(x,y) on the boundary. The finite element method is used, with triangular elements, which must be a 3 node linear triangle. Node file is "ell_nodes.txt". Element file is "ell_elements.txt". Number of nodes = 65 First 10 nodes Row: 1 2 Col 1 0 0 2 0 0.5 3 0.5 0 4 0 1 5 0.5 0.5 6 1 0 7 0 1.5 8 0.5 1 9 1 0.5 10 1.5 0 Element order = 3 Number of elements = 96 First 10 elements Row: 1 2 3 Col 1 1 3 2 2 6 5 3 3 4 2 5 4 3 5 2 5 23 22 10 6 21 9 22 7 6 10 9 8 22 9 10 9 19 7 20 10 4 8 7 Quadrature order = 3 Number of nonzero coefficients NZ_NUM = 385 ITR = 1 Residual = 68.3088 K = 1 Residual = 50.3097 K = 2 Residual = 33.4221 K = 3 Residual = 18.722 K = 4 Residual = 9.71637 K = 5 Residual = 5.43785 K = 6 Residual = 2.86222 K = 7 Residual = 1.51663 K = 8 Residual = 0.632429 K = 9 Residual = 0.224386 K = 10 Residual = 0.0707548 K = 11 Residual = 0.0264148 K = 12 Residual = 0.00649285 K = 13 Residual = 0.0021897 K = 14 Residual = 0.000657136 K = 15 Residual = 0.000180903 K = 16 Residual = 6.05025e-05 K = 17 Residual = 2.64275e-05 K = 18 Residual = 1.44706e-05 K = 19 Residual = 2.49499e-06 K = 20 Residual = 9.72453e-07 MGMRES Number of iterations = 20 Final residual = 9.72453e-07 Part of the solution vector vector U: 1 -1.73746e-12 2 0.25 3 0.25 4 1 5 0.484936 6 1 7 2.25 8 1.22891 9 1.22891 10 2.25 FEM2D_POISSON_SPARSE: Wrote an ASCII file "ell_solution.txt". of the form U ( X(I), Y(I) ) which can be used for plotting. FEM2D_POISSON_SPARSE: Normal end of execution. 25 January 2013 02:22:12 PM