Output is not reproducible

[baraaorabi]

In line 1505 of the simulator.py script:

NanoSim/src/simulator.py

Lines 1504 to 1506 in 23911b6

	for i in range(num_threads):
	np.random.seed()
	random.seed()

The seed is reset before each process/thread is started. This overrides the setting of the random seed in here:

NanoSim/src/simulator.py

Lines 2180 to 2181 in 23911b6

	random.seed(int(args.seed))
	np.random.seed(int(args.seed))

It also causes the the output of Nanosim to be not reproducible despite using the same value for the --seed arg. I think these two lines (L1505 and L1506) should be dropped. Or maybe they should be replaced with something like?

deterministically_random_seed = random.getrandbits(32)
np.random.seed(deterministically_random_seed) 
random.seed(deterministically_random_seed)

This would give each thread a new random seed that is deterministically defined by the --seed value which should ensure reproducibility across runs with the same --seed.

[kmnip]

Thanks Baraa!
I agree with you. I have suspicions that this is an issue when I was reading through simulator.py recently.
@SaberHQ and I will look into it!

[schorlton-bugseq]

Hi @kmnip , is there a reason we would need to seed repetitively by the number of threads or can we remove these lines as suggested by @baraaorabi to enable reproducibility? Happy to MR if appropriate. Thanks for your consideration!