Learning Forum

[gangin2]

Hello,

I am running a topology optimization of a 90 degree bend (see below).

The topology python script I adapted from the example on the website can run the zero-th iteration and it gets to the structure above.  However, it cannot run the next iteration.

This is the terminal output:

At iterate    0    f= -1.27792D+01    |proj g|=  2.50000D-01
Making forward solve
Making adjoint solve
Running solves
Processing forward solve
Traceback (most recent call last):
  File "E:\Documents\Research\Lumerical\Inverse\bend\bend_opt2.py", line 74, in
    runSim(initial_cond, eps_min, eps_max, x_pos, y_pos, filter_R*1e-9, working_dir)
  File "E:\Documents\Research\Lumerical\Inverse\bend\bend_opt2.py", line 45, in runSim
    opt.run(working_dir = working_dir)
  File "C:\Program Files\Lumerical\v241\api\python\lumopt\optimization.py", line 582, in run
    self.optimizer.run()
  File "C:\Program Files\Lumerical\v241\api\python\lumopt\optimizers\generic_optimizers.py", line 50, in run
    res = spo.minimize(fun = self.callable_fom,
  File "C:\Program Files\Lumerical\v241\python\Lib\site-packages\scipy\optimize\_minimize.py", line 609, in minimize
    return _minimize_lbfgsb(fun, x0, args, jac, bounds,
  File "C:\Program Files\Lumerical\v241\python\Lib\site-packages\scipy\optimize\lbfgsb.py", line 345, in _minimize_lbfgsb
    f, g = func_and_grad(x)
  File "C:\Program Files\Lumerical\v241\python\Lib\site-packages\scipy\optimize\lbfgsb.py", line 295, in func_and_grad
    f = fun(x, *args)
  File "C:\Program Files\Lumerical\v241\python\Lib\site-packages\scipy\optimize\optimize.py", line 327, in function_wrapper
    return function(*(wrapper_args + args))
  File "C:\Program Files\Lumerical\v241\api\python\lumopt\optimizers\minimizer.py", line 24, in callable_fom_local
    fom = callable_fom(params_over_scaling_factor)
  File "C:\Program Files\Lumerical\v241\api\python\lumopt\optimization.py", line 781, in callable_fom
    fom = self.process_forward_sim(iter)
  File "C:\Program Files\Lumerical\v241\api\python\lumopt\optimization.py", line 714, in process_forward_sim
    Optimization.check_simulation_was_successful(self.sim)
  File "C:\Program Files\Lumerical\v241\api\python\lumopt\optimization.py", line 1027, in check_simulation_was_successful
    raise UserWarning('FDTD simulation did not complete successfully: status {0}'.format(simulation_status))
UserWarning: FDTD simulation did not complete successfully: status 0.0

 

If I check the log file, it states "Error: there was an unknown parallel error. The error code is 0, the process number is 5" for both the forward and adjoint solves.

 

Once the script fails, I can independently run the simulation files that it has created for the forward and adjoint solves.  They will also crash but give more details:

From this error message, since I am doing a narrowband varFDTD simulation I tried following the suggestion and unchecked "can optimize mesh algorithm for extruded structures."  However doing that does not solve the issue and I'm not sure how I can resolve the next error:

Any help would be appreciated.  Thank you!

[Fatema Chowdhury]

Hello,

According to Optimizable Geometry - Python API – Ansys Optics, one should work with FDTD for all topology optimizations. Therefore, I would first suggest that  you kindly try FDTD instead of varFDTD.

For further support, resolving the issue without the access to the file could be difficult. Debugging such issues with a specific file is beyond the scope of ALF. I recommend that  you can kinldy create a case in ACSS (https://customer.ansys.com/) to provide you proper support. To know more about ACSS,please use this link(https://optics.ansys.com/hc/en-us/articles/5609426062483-How-to-register-on-Ansys-Customer-Support-Space)