fem

所属分类:数学计算
开发工具:matlab
文件大小:95KB
下载次数:104
上传日期:2012-07-14 02:05:38
上 传 者triospi
说明:  一个用MATLAB写的二维矩形有限元算法,包括网格剖分和演示程序
(Using MATLAB to write the two-dimensional rectangular finite element algorithms, including mesh generation and demo program)

文件列表:
fem\adapt1.m (2166, 2003-09-02)
fem\demo\ex1.m (47472, 2003-09-02)
fem\demo\ex1.mat (80152, 2003-09-02)
fem\demo\ex2.m (140862, 2003-09-02)
fem\demo\ex2.mat (278168, 2003-09-02)
fem\demo\test1.m (832, 2003-09-02)
fem\demo\test2.m (1711, 2003-09-02)
fem\fem1.m (2642, 2003-09-02)
fem\fem2.asv (4202, 2012-07-13)
fem\fem2.m (4248, 2003-09-02)
fem\genmat1.m (1599, 2003-09-02)
fem\genmat2.m (1772, 2003-09-02)
fem\genmat3.m (2100, 2003-09-02)
fem\genmesh2.m (1881, 2003-09-02)
fem\impmesh.m (551, 2003-09-02)
fem\meshtest.m (367, 2003-09-02)
fem\plotgrid2.m (800, 2003-09-02)
fem\quadspace.m (674, 2003-09-02)
fem\refine1.m (1156, 2003-09-02)
fem\vmean.m (282, 2003-09-02)
fem\demo (0, 2003-09-02)
fem (0, 2012-07-13)

Finite Element Toolbox Ver. 2.1 =============================== Date: 2002-04-01 Author: B. Rasmus Anthin. WHAT IS IT ---------- This is a toolbox for computing ODEs or PDEs in BVPs using FEM in 1D, 2D and 3D. * FEM1 this is the main routine for solving ODE BVPs using any combination of Dirichlet, Neumann or Robin conditions. * GENMAT1 called by FEM1 and is the core of the program. It generates the matrices used for solving the linear equation system for the ODE. * REFINE1 with this routine you can refine the mesh over certain critical grid points. The the gridpoints will become nonuniformly linearly spaced. * TEST1 this is a test for the 1D case of FEM. Look through this example carefully in order to fully understand how FEM1 works. * FEM2.mat contains examples over meshes/triangulations in 2D. * PLOTGRID2 plot mesh/triangulation in 2D and put a number in each corresponding element (triangle). * QUADSPACE generates quadratically spaced vectors. That is, the spaces are linearly decreasing/increasing. * FEM2 this is the main routine for solving PDE BVPs using any combination of Dirichlet, Neumann or Robin conditions. * GENMAT2 called by FEM2 and is the core of the program. It generates the matrices used for solving the linear equation system for the PDE. * TEST2 test for the 2D case of FEM. Test this for better learning how to use FEM2 and other utilities. INSTALLATION ------------ 0. UNINSTALLATION: If you already have one of the earlier distributions, then the best thing would be if you could remove the earlier archive and then go proceed to the next step (2) below. To remove the archive simply enter the "fem" directory and in Unix/Linux write "rm -rf". Please be sure that you REALLY are in the current directory or else other valuable files may be lost FOREVER! So use "rm -rf" with great caution!!! You should not have any of your own files located in this directory if you are running Matlab under Unix/Linux! If you are running Matlab under Windows then use either "Windows Commander" or the Windows built in "File Explorer" in order to delete the earier installed archive. 1. Enter your matlab directory or the directory where you want to put the toolbox. 2. Place the fem.#.#.zip archive file in this directory. 3. Linux/Unix: Install by writing "gunzip fem.#.#.zip" (you can also use "unzip" as well). Windows: Copy the entire archive to the directory using Windows Commander available from "http://www.ghisler.com", or use WinZip. You should then end up with a file structure like this: /fem/ fem1.m genmat1.m . . 4. Update your matlab path using the command "pathtool" or "editpath" if you have not done this already. If you would encounter any problems during the above steps, the please contact me "e8rasmus@etek.chalmers.se" and I'll do my best to help you through. GETTING STARTED --------------- Look at the included examples, such as TEST1. And use help for a function for more info on how it works. UPDATES AND VERSIONS -------------------- Ver 1.0: Only 1D case implemented. Works good. However the routines are very unefficient due to that I'm integrating over each pair of basis functions. Ver 1.1: Using sparse matrices in the implentation of GENMAT1 described above. This yields more efficient calculations and a grid size of 5000 only takes a couple of seconds on a unix-machine. Ver 1.2: Error discovered in GENMAT1: A division with three was not done on the vector at the right side of the equation. The refinement algorithm now works properly (REFINE1). Earlier the refinement took place only between the adjacent points of the refinement- points and the refinement was exponential. Now the refinement is done with linearly increasingly/decreasingly spaced grids and is much more smoth. See REFINE1 and QUADSPACE for more info. Ver 1.3: Removed the Neumann special case. This is otherwise easily acheived by setting GAMMA to zero in the Robin boundary conditions. Added GENMAT2 and FEM2. GENMAT2 is generally completed but will be improved later on. FEM2 is not completed and should not be used. Ver 2.0: Major changes of syntax. Completed the 2D FEM solver. However the boundary orientation checking is not yet implemented and satisfactory. However it should work well for most cases if you design the Robin boundaries having the desired orientation. Ver 2.1: No this is no aprils fool joke. I think I have removed all bugs in the FEM2 program. TEST2 is updated accordingly (take a glance on it in order to better understand how the syntax is supposed to be). The orientation is the same as how the order of nodes are entered in the corresponding boundary matrix. The boundary-matrices are inputed to the FEM2 as a cell-array of boundary condition matrices (see FEM2). EOF.

近期下载者

相关文件


收藏者