Stiffness Matrix
A test build of FEMM has been made that dumps the stiffness matrix and right-hand side prior to solving a 2D magnetostatic problem. The installation files and source code for this test build are available at the bottom of the page.
To tell the solver that it should dump the stiffness matrix and rhs, the string "dump" should be placed as the comment in the
Problem Definition dialog. The comment can also be set programmatically using new mi_setcomment() command.
An example .fem file is also included below with the comment set as indicated above. When the analysis is run, the program will make two files with the same root name as the .fem file but with the .m and .dat extensions. It is assumed that the matrix will be imported into either Matlab or Octave. To load the matrix, you should run the .m file as a script. It will create a vector, \(b\), in the workspace and it will load the .dat file and turn its contents into a sparse matrix, \(M\), also located in the workspace.
The solution can be queried in FEMM to get information about the node and element structure of the problem.
| File | Last modified | Size |
|---|---|---|
| junk.fem | 2021-07-05 18:42 | 6Kb |
| pyfemm-013.zip | 2021-07-20 19:48 | 17Kb |
| __init__.py | 2021-07-17 17:01 | 49Kb |
| femm42src_03Jul2021.zip | 2021-07-11 20:23 | 2Mb |
| femm42bin_win32_03Jul2021.exe | 2021-07-11 20:23 | 7Mb |
| femm42bin_x64_03Jul2021.exe | 2021-07-11 20:23 | 9Mb |