allocate_tod=False not working

[paganol]

The constructor of Observations calls

litebird_sim/litebird_sim/observations.py

Line 126 in 35b67ba

self.setattr_det_global("det_idx", np.arange(self._n_detectors_global), root)

which assumes that the tod attribute exists. This is not true when allocate_tod is set to false

[ziotom78]

Hi @paganol, thanks for the report. It's not obvious to me why Observation.setattr_det_global should mess with the TOD, but it's probably due to consistency checks (the field self.tod appears twice in the body of the method, and in both cases it is within an assert), so it is probably ok to avoid them if self.tod is None.

@dpole , what do you think?