Varying plt output behavior in pyfun

[nasa-ddalle]

I'm also thinking that this can be used to drive a simulation to a certain number of steps, and then setting up a new folder where we can dump out plt files for every _boundary_animationfreq steps so that we can average those plt files for visualizations. This would be a nice ability because FUN3D otherwise periodically generates plt files every _boundary_animationfreq steps for the entire iteration history (rather than say for steps > N), which can be cumbersome.

Originally posted by @rbreslavsky in https://github.com/nasa/cape/issues/6#issuecomment-1474071352

[nasa-ddalle]

I think you can already accomplish the desired behavior, either with WarmStart or without, but having a new phase and just having boundary_animation_freq different for the last phase. It should look something like this:

"RunControl": {
    "PhaseSequence": [0, 1, 2],
    "PhaseIters": [1000, 1500, 2000],
    "nodet": {
        "animation_freq": [-1, -1, 10],
        "plt_tecplot_output": true
    }
},
"Fun3D": {
    "global": {
        "boundary_animation_freq": [-1, -1, 10]
    }
}

With these settings FUN3D should dump out a .plt file at iterations 1000, 1500, 1510, 1520, ...

I never fully figured out the interaction between the command-line setting nodet > animation_freq and the namelist setting global > boundary_animation_freq, so I just set them both in this example to be safe.