O autor do gmsh explica como escolher o formato 2.2 nos arquivos .msh. Isto facilita a rotina de leitura da malha.
> On 24 Mar 2020, at 05:33, Andress <randalandress1507 at comcast.net> wrote:
>
> Is it possible to set MSH file format to 2 as an option for the later versions (4.5.4) of Gmsh, so that when the .msh is saved from the GUI, it will produce MSH2 instead of MSH4 ascii files?
>
Sure. With the GUI, select File->Export, enter a .msh filename, then select the format you want in the dropdown menu. Then use File->Save Options as Default. This will save your options in ~/.gmsh-options.
See also FAQ 17 in http://gmsh.info/doc/texinfo/gmsh.html#Mesh-module-questions:
```
How can I save a mesh file with a given (e.g. older) MSH file format version?
• In the GUI: open ‘File->Export’, enter your filename.msh and then pick the version in the dropdown menu.
• On the command line: use the -format option (e.g. gmsh file.geo -format msh2 -2).
• In a .geo script: add the line Mesh.MshFileVersion = x.y; for any version number x.y. You can also save this in your default options.
• In the API: gmsh::option::setNumber("Mesh.MshFileVersion", x.y).
As an alternative method, you can also not specify the format explicitly, and just choose a filename with the .msh2 or .msh4 extension.
```
Christophe