06 December 2010 09:07:58 PM FFP_SPARSE: C++ version: Compiled on Dec 6 2010 at 21:05:35. A version of FREE_FEM_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 "lake_nodes.txt". Triangle file is "lake_elements.txt". Number of nodes = 621 First 10 nodes Row: 1 2 Col 1 316.43 404.476 2 291.049 400.709 3 265.165 409.779 4 241.468 402.403 5 216.551 396.521 6 163.285 411.371 7 142.818 391.164 8 111.954 346.703 9 100.035 325.727 10 103.987 302.516 Element order = 3 Number of elements = 974 First 10 elements Row: 1 2 3 Col 1 619 618 39 2 620 619 39 3 125 126 7 4 125 132 126 5 143 135 150 6 143 154 150 7 481 482 69 8 454 464 68 9 460 473 472 10 460 450 472 Quadrature order = 3 Number of nonzero coefficients NZ_NUM = 3811 ITR = 1 Residual = 2.61618e+07 K = 1 Residual = 7759.88 K = 2 Residual = 4033.04 K = 3 Residual = 2064.68 K = 4 Residual = 1043.06 K = 5 Residual = 590.617 K = 6 Residual = 322.866 K = 7 Residual = 216.484 K = 8 Residual = 135.267 K = 9 Residual = 86.7598 K = 10 Residual = 60.0294 K = 11 Residual = 41.0438 K = 12 Residual = 29.887 K = 13 Residual = 24.2582 K = 14 Residual = 21.8413 K = 15 Residual = 20.75 K = 16 Residual = 20.2328 K = 17 Residual = 20.0105 K = 18 Residual = 19.7626 K = 19 Residual = 19.39 K = 20 Residual = 18.3958 ITR = 2 Residual = 18.3958 K = 1 Residual = 18.3958 K = 2 Residual = 17.7722 K = 3 Residual = 17.477 K = 4 Residual = 17.316 K = 5 Residual = 17.1703 K = 6 Residual = 16.9056 K = 7 Residual = 16.5692 K = 8 Residual = 16.1985 K = 9 Residual = 14.9125 K = 10 Residual = 12.7793 K = 11 Residual = 10.9527 K = 12 Residual = 8.89099 K = 13 Residual = 6.86045 K = 14 Residual = 4.80118 K = 15 Residual = 2.83188 K = 16 Residual = 1.65976 K = 17 Residual = 0.981748 K = 18 Residual = 0.665924 K = 19 Residual = 0.420939 K = 20 Residual = 0.23593 ITR = 3 Residual = 0.23593 K = 1 Residual = 0.235929 K = 2 Residual = 0.164212 K = 3 Residual = 0.105276 K = 4 Residual = 0.0733652 K = 5 Residual = 0.0472247 K = 6 Residual = 0.0279413 K = 7 Residual = 0.0168423 K = 8 Residual = 0.0112185 K = 9 Residual = 0.00814604 K = 10 Residual = 0.00584313 K = 11 Residual = 0.00452534 K = 12 Residual = 0.0035452 K = 13 Residual = 0.00314373 K = 14 Residual = 0.00288613 K = 15 Residual = 0.00271897 K = 16 Residual = 0.00265755 K = 17 Residual = 0.00263704 K = 18 Residual = 0.00262256 K = 19 Residual = 0.00260362 K = 20 Residual = 0.00254773 ITR = 4 Residual = 0.00254773 K = 1 Residual = 0.00254773 K = 2 Residual = 0.00249656 K = 3 Residual = 0.00245217 K = 4 Residual = 0.00239541 K = 5 Residual = 0.00235476 K = 6 Residual = 0.00231478 K = 7 Residual = 0.00226651 K = 8 Residual = 0.00217984 K = 9 Residual = 0.00188785 K = 10 Residual = 0.00138505 K = 11 Residual = 0.000891985 K = 12 Residual = 0.000600455 K = 13 Residual = 0.000445268 K = 14 Residual = 0.000323834 K = 15 Residual = 0.000218869 K = 16 Residual = 0.000137001 K = 17 Residual = 7.27478e-05 K = 18 Residual = 4.1307e-05 K = 19 Residual = 2.39361e-05 K = 20 Residual = 1.58444e-05 ITR = 5 Residual = 1.58444e-05 K = 1 Residual = 1.58444e-05 K = 2 Residual = 1.21051e-05 K = 3 Residual = 7.39224e-06 K = 4 Residual = 4.48493e-06 K = 5 Residual = 2.85693e-06 K = 6 Residual = 1.85714e-06 K = 7 Residual = 1.45445e-06 K = 8 Residual = 1.17322e-06 K = 9 Residual = 1.02677e-06 K = 10 Residual = 9.15247e-07 MGMRES Number of iterations = 90 Final residual = 9.15247e-07 FFP_SPARSE:: Wrote an ASCII file "lake_solution.txt". of the form U ( X(I), Y(I) ) which can be used for plotting. FFP_SPARSE:: Normal end of execution. 06 December 2010 09:07:58 PM