Spectool usage questions

[msabbah06]

Hello,

Thank you very much for your work ! I have been hinted by @AjSat to use spectool and fatrop to solve my problem and it seems very promising !

What I want to do is to perform MHE for human kinematics estimation. The big challenge is that I want to integrate this into a realtime pipeline and the MHE part should not exceed 5 ms to be ideal.
I formulated my problem in the following code : https://gitlab.laas.fr/msabbah/rt-cosmik/-/blob/main/utils/ik_utils.py?ref_type=heads#L599
For now, with codegen and a naive warm start of the solver, I benchmarked the resolution around 10 ms (best case scenario) to 50-60 ms (it can happen quite often depending on the measures I want to track). Thus, to fit my requirements I need to still improve the speed of resolution a bit. I already tried to tune the solver parameters (like the tolerance was set to 1e-3, and I also tried to change the number of max_iter in order to cap the resolution time, but the solver throw an error in this case). But I am willing to learn even more about this.

Therefore, I have several questions about the use of spectool :

1. I use jit to codegen my problem. However the compilation can take up to 30 minutes (since a lot of files are generated). For now I did not find any way to use what has been previously compiled to accelerate future resolutions of my problem. Therefore I wanted to know, if I can do codegen once and for all for my problem and then call whatever has been generated in spectool to bypass a new compilation ?
2. I have been told that evaluations of functions can be parallelized but I yet don't know how to do this. I think it can help to solve my problem even more quicker.
3. I set a naive warmstart with all the states and controls over my horizon to be at the value of the first state and control of the window. I think this can be improved by setting a different warmstart at each timestep but I did not know how to do this and it ended up with errors when I tried.

In any cases, I am really keen to know if I miswrote my problem or if they are way more efficient to formulate what I want to do. My usecase is not very complex on its own I believe, but it takes a little bit of mastery to achieve the timings that I want.

Best regards,

Maxime