Cannot handle uncertainties in quantities

[kyleniemeyer]

As of v0.2.3, PyTeCK cannot handle ChemKED files with uncertainties (at least in ignition delay, and likely other quantities).

For example, in eval_model,

        ign_delay = [case.ignition_delay.to('second').magnitude
                     for case in properties.datapoints
                     ]

doesn't work when the ignition delays have uncertainties, because case.ignition_delay is now a Measurement type that does not have the method magnitude. Instead, it needs to be case.ignition_delay.to('second').value.magnitude (I think).

[kyleniemeyer]

possibly fixed in 1442f91 / v0.2.4a1

[skrsna]

I'm running into similar issues while trying to run PyTeCK with ChemKED files with uncertainties in ignition delays. Specifically at this line, which makes PressureRiseProfile. The error I'm getting is as follows:

/home/sirumalla.s/anaconda3/envs/pyteck/lib/python3.6/site-packages/pyteck/eval_model.py:169: RuntimeWarning: Warning: multiple changing variables. Using temperature.
  RuntimeWarning
multiprocessing.pool.RemoteTraceback: 
"""
Traceback (most recent call last):
  File "/home/sirumalla.s/anaconda3/envs/pyteck/lib/python3.6/multiprocessing/pool.py", line 119, in worker
    result = (True, func(*args, **kwds))
  File "/home/sirumalla.s/anaconda3/envs/pyteck/lib/python3.6/multiprocessing/pool.py", line 44, in mapstar
    return list(map(*args))
  File "/home/sirumalla.s/anaconda3/envs/pyteck/lib/python3.6/site-packages/pyteck/eval_model.py", line 79, in simulation_worker
    sim.setup_case(model_file, model_spec_key, path)
  File "/home/sirumalla.s/anaconda3/envs/pyteck/lib/python3.6/site-packages/pyteck/simulation.py", line 363, in setup_case
    self.time_end
  File "/home/sirumalla.s/anaconda3/envs/pyteck/lib/python3.6/site-packages/pyteck/simulation.py", line 255, in __init__
    reactants, pressure_rise, time_end
  File "/home/sirumalla.s/anaconda3/envs/pyteck/lib/python3.6/site-packages/pyteck/simulation.py", line 85, in create_volume_history
    [times, pressures] = sample_rising_pressure(time_end, pres, freq, pres_rise)
  File "/home/sirumalla.s/anaconda3/envs/pyteck/lib/python3.6/site-packages/pyteck/simulation.py", line 61, in sample_rising_pressure
    times = np.arange(0.0, time_end + (1.0 / freq), (1.0 / freq))
  File "/home/sirumalla.s/anaconda3/envs/pyteck/lib/python3.6/site-packages/uncertainties/core.py", line 2670, in raise_error
    % (self.__class__, coercion_type))
TypeError: can't convert an affine function (<class 'uncertainties.core.AffineScalarFunc'>) to float; use x.nominal_value
"""

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "test_performance.py", line 18, in <module>
    skip_validation=True
  File "/home/sirumalla.s/anaconda3/envs/pyteck/lib/python3.6/site-packages/pyteck/eval_model.py", line 366, in evaluate_model
    results = pool.map(simulation_worker, jobs)
  File "/home/sirumalla.s/anaconda3/envs/pyteck/lib/python3.6/multiprocessing/pool.py", line 266, in map
    return self._map_async(func, iterable, mapstar, chunksize).get()
  File "/home/sirumalla.s/anaconda3/envs/pyteck/lib/python3.6/multiprocessing/pool.py", line 644, in get
    raise self._value
TypeError: can't convert an affine function (<class 'uncertainties.core.AffineScalarFunc'>) to float; use x.nominal_value

The ChemKED file that's causing this can be found here.
I googled the error and ended up at official Uncertainties repo issue page here. Hope this helps. If you want to reproduce the error I can point you to our private repo on CoMoChEng organization. Thanks

[kyleniemeyer]

@skrsna can you share the other files you were using when you ran into this error, so I can replicate the issue?