`weight=0` for `_broadcast_input='Node'` fails

[YigitElma]

MWE:

eq = get("precise_QA")
coils = initialize_modular_coils(eq, num_coils=3, r_over_a=2)
# runs fine
obj = ObjectiveFunction(CoilLength(coils, weight=[0, 1, 2]))
obj.build()

# fails
obj = ObjectiveFunction(CoilTorsion(coils, weight=[0, 1, 2]))
obj.build()

Currently, the masking of the coil objective by weight=0 trick doesn't work if the objective returns quantities on each node of the grid. There are multiple things to fix:

• This line fails since fancy indexing of python lists with numpy arrays is not possible
• obj._coilset_tree["coilset_mask"] doesn't have proper length to index grid which has length num_coils

@singh-jaydeep, can you think of any simple fix?

[singh-jaydeep]

Jeez, that's my bad. We can keep a separate coil_mask (always of length num_coils) and grid_mask, so the coil_mask can be used here. I'll add this today, as well as some tests to cover this case.