Example powersystem.py doesn't work at all

[dietmarwo]

Steps to reproduce

1. pip install nevergrad
2. git clone git@github.com:facebookresearch/nevergrad.git
3. cd nevergrad/examples
4. python powersystem.py
5. using anaconda python 3.9 on Linux Mint 20.3.

Observed Results

• What happened? This could be a description, log output, etc.

ana39/lib/python3.9/site-packages/nevergrad/optimization/base.py:146: InefficientSettingsWarning: num_workers = 10 > 1 is suboptimal when run sequentially warnings.warn(msg, e) Traceback (most recent call last): File "/home/xxx/sich/examples/powersystem.py", line 43, in optimizer.minimize(power_system_loss) File "/home/xxx/ana39/lib/python3.9/site-packages/nevergrad/optimization/base.py", line 641, in minimize result = job.result() File "/home/xxx/ana39/lib/python3.9/site-packages/nevergrad/optimization/utils.py", line 137, in result self._result = self.func(*self.args, *self.kwargs) File "/home/xxx/ana39/lib/python3.9/site-packages/nevergrad/functions/base.py", line 119, in call return self.function(args, **kwargs) File "/home/xxx/ana39/lib/python3.9/site-packages/nevergrad/functions/powersystems/core.py", line 129, in _simulate_power_system agent.set_parameters(array) File "/home/xxx/ana39/lib/python3.9/site-packages/nevergrad/functions/powersystems/core.py", line 37, in set_parameters raise ValueError(f"length = {weights.size} instead of {self.dimension}: {weights}.") ValueError: length = 7560 instead of 1260: [-0.73698052 1.41931025 1.34390607 ... -0.79129847 -0.77101758 -0.6903909 ].

Expected Results

• What did you expect to happen?

Expected "optimizer.minimize(power_system_loss)" to perform some optimization and "power_system_loss.make_plots" to show some plots.

As it is the one and only nevergrad example the observed result is a bit disappointing.

[Elcomiqu321]

`import nevergrad as ng from nevergrad.functions.powersystems.core import PowerSystem

budget = 3500 width = 6 depth = 6 num_dams = 6 year_to_day_ratio = 0.5 back_to_normal = 0.5 num_thermal_plants = 6 constant_to_year_ratio = 4.0

power_system_loss = PowerSystem( num_dams=num_dams, depth=depth, width=width, year_to_day_ratio=year_to_day_ratio, back_to_normal=back_to_normal, num_thermal_plants=num_thermal_plants, constant_to_year_ratio=constant_to_year_ratio, )

added line:

param = int(power_system_loss.dimension/power_system_loss.num_dams)

changed 'parametrization=power_system_loss.dimension' in the optimizer parameters:

optimizer = ng.optimizers.SplitOptimizer( parametrization=param, budget=budget, num_workers=1 )

optimizer.minimize(power_system_loss) power_system_loss(optimizer.provide_recommendation().value) power_system_loss.makeplots( f"ps{numdams}dams{depth}_{width}_ytdr{year_to_day_ratio}_btn{back_to_normal}" f"_num_thermal_plants{num_thermal_plants}_ctyr{constant_to_year_ratio}_budget{budget}.png" )`