19 August 2018 05:19:08 PM FEM2D_POISSON_CG: C++ version: Compiled on Aug 19 2018 at 17:19:08. A version of FEM2D_POISSON using sparse storage and a conjugate gradient 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 Step Residual 1 39.3312 2 23.1596 3 10.7601 4 6.12728 5 3.47712 6 1.6552 7 0.59265 8 0.162597 9 0.0693399 10 0.0241027 11 0.00609233 12 0.00162877 13 0.000299049 14 6.70415e-05 15 4.38113e-06 Number of iterations was 15 Estimated error is 7.44849e-08 Part of the solution vector vector U: 1 0 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 Wrote an ASCII file "ell_values.txt". of the form U ( X(I), Y(I) ) which can be used for plotting. FEM2D_POISSON_CG: Normal end of execution. 19 August 2018 05:19:08 PM