# Now it looks like I can load the mpi code ok even without mpirun

**URL:** <https://community.freefem.org/t/now-it-looks-like-i-can-load-the-mpi-code-ok-even-without-mpirun/2243>\
**Category:** General Discussion\
**Created:** [January 23, 2023, 8:32pm UTC](https://community.freefem.org/t/now-it-looks-like-i-can-load-the-mpi-code-ok-even-without-mpirun/2243 "2023-01-23T20:32:57Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![marchywka](https://avatars.discourse-cdn.com/v4/letter/m/ee59a6/32.png) [@marchywka](https://community.freefem.org/u/marchywka)\
**Post date:** [January 23, 2023, 8:32pm UTC](https://community.freefem.org/t/now-it-looks-like-i-can-load-the-mpi-code-ok-even-without-mpirun/2243/1 "2023-01-23T20:32:57Z")

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Curious now though if there is an incompatibility between the mpi that comes with  
the ff petsc and openmpi. It looks like my original concern was sensible- ff was  
passing a list of strings without a count and without a null terminator that  
was expected by the MPI implementation. Not sure if there are other diffs  
or if that too was just spurious but still may be worth tracking down at some point.

I haven’t cone back to the “make check” fails but since this now works in my development  
setting, Since there is no obvious way to be sure of mpi code being included, when  
you are a few levels deep in includes, some kind  
of better failure modes may be helpful.

ff-mpirun -np 4 Helmholtz\_circle\_Neumann.edp -wg

I’m assuming for the most part it is ok now. Have to find out what “-wg” does as  
it seems required to get the plots to pop up.

I did note in the manual something about a real wave vector requirement.  
As I was thinking about lossy media, what is the origin of this or is  
complex ok? Still digging through the examples , cobra right now,  
thinking about simple capacitor with plates connected by an “inductor”  
lol. With ideal materials it may still have radiation losses 🙂 I guess if the cobracavity  
geometry was tractable this may be too. Should be more fun now if  
the computer stuff works 🙂  
Thanks.

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**Author:** ![aszaboa](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.freefem.org/aszaboa/32/2918_2.png) [@aszaboa](https://community.freefem.org/u/aszaboa)\
**Post date:** [January 24, 2023, 11:10pm UTC](https://community.freefem.org/t/now-it-looks-like-i-can-load-the-mpi-code-ok-even-without-mpirun/2243/2 "2023-01-24T23:10:18Z")

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If you type FreeFem++ into the command lin you see that `-wg` means “with graphics”.  
For MPI graphics, I recommend using vtk output, or the following repo with a global mesh output: [GitHub - samplemaker/freefem\_matlab\_octave\_plot: Examples how to plot FreeFem++ simulation results from within matlab and octave](https://github.com/samplemaker/freefem_matlab_octave_plot)