10 September 2006 07:50:01 AM FREE_FEM_HEAT (C++ version): Solution of the time dependent heat equation on an arbitrary triangulated region D in 2 dimensions. Ut - Uxx - Uyy + K(x,y,t) * U = F(x,y,t) in D U = G(x,y,t) on the boundary. U = H(x,y,t) at initial time. The finite element method is used with 6 node quadratic triangular elements ("T6"). The time derivative is approximated using the backward Euler method. Current status: * The time step information must be set internally. * Would be easy to do linear triangles as well. * Do you want ability to compare exact solution? Node file is "square_nodes.txt". Element file is "square_elements.txt". Number of nodes = 81 First 10 nodes Row: 1 2 Col 1 0 0 2 0.125 0 3 0.25 0 4 0.375 0 5 0.5 0 6 0.625 0 7 0.75 0 8 0.875 0 9 1 0 10 0 0.125 Element order = 6 Number of elements = 32 First 10 elements Row: 1 2 3 4 5 6 Col 1 1 19 3 10 11 2 2 21 3 19 12 11 20 3 3 21 5 12 13 4 4 23 5 21 14 13 22 5 5 23 7 14 15 6 6 25 7 23 16 15 24 7 7 25 9 16 17 8 8 27 9 25 18 17 26 9 19 37 21 28 29 20 10 39 21 37 30 29 38 Quadrature order = 3 The matrix half bandwidth is 18 The matrix bandwidth is 37 The storage bandwidth is 55 Initial time = 0 Final time = 0.5 Step size = 0.05 Number of steps = 10 Wrote solution file "u0000.txt" for time T = 0 Time L2 Error H1 Error Wrote solution file "u0001.txt" for time T = 0.05 Wrote solution file "u0002.txt" for time T = 0.1 Wrote solution file "u0003.txt" for time T = 0.15 Wrote solution file "u0004.txt" for time T = 0.2 Wrote solution file "u0005.txt" for time T = 0.25 Wrote solution file "u0006.txt" for time T = 0.3 Wrote solution file "u0007.txt" for time T = 0.35 Wrote solution file "u0008.txt" for time T = 0.4 Wrote solution file "u0009.txt" for time T = 0.45 Wrote solution file "u0010.txt" for time T = 0.5 FREE_FEM_HEAT: Normal end of execution. 10 September 2006 07:50:01 AM