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Additional notes

- Be sure to define all subdomains vertices in a counter-clockwise direction. Failing to do so can result in elements with negative volumes.
- When joining two subdomains together, all three nodes of the sides must match.
- For complicated regions, carefully plan your mesh on paper before attempting to generate it. If you will be making curved sides, this is especially important. It may be worthwhile to write all of the vertex coordinates for each subdomain on paper and then manually enter them in the vertex position edit boxes.
- When you add a new subdomain onto already existing ones, the number of divisions on joined sides will be inherited.
- Many of the edit boxes use the function `str2num` to read the input. The advantage of this is that you can type function names such as `sin`, `cos`, and `pi`. The disadvantage is that mismatched spaces can result in errors. Read the documentation for `str2num` or just avoid typing spaces in the edit boxes.
- If you notice an error in your subdomain after you have already pressed the Save SD button, continue entering the information for rest of the SDs in your domain. After you have finished defining all SDs, you can fix any errors during the review process.
- It is possible to run the program mesh_3tri without the MappingMeshTool. There are two main reasons you might want to do this:
  1. made a mistake when drawing and failed to fix it during the review process, or
  2. want a variation on an existing mesh.
  You should only take this route if your domain is complicated and it would be very time consuming to draw it again. However, it is possible to alter the mesh generation file by hand. An example of the first situation is if one vertex is in the wrong position. You could fix the coordinates in the mesh generation file, then run mesh_3tri. An example of wanting a slight variation on an existing mesh would be if you want to refine a complicated mesh. You could alter the number of divisions in each direction on the various subdomains, then run mesh_3tri.
  In order to run the meshing program, at the Matlab command line type `mesh_3tri`. You will be prompted for the mesh generation file and also the mesh file name (usually with the suffix _mesh.dat).
  The likelihood of an ill-formed mesh generation file is much lower if you use the MappingMeshTool rather than creating one by hand. Avoid using this method if possible. The greatest benefit of using MappingMeshTool is in defining the join array, which is automated in that program but an error-prone process by hand.

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