[Usage question] - Difference between trajectory and insertion

[GaelleChapuis]

Describe the question you have
Asking and answering questions from @anne-urai here:
Q: What is the difference between insertion and trajectory?
A: An insertion is unique per physical probe insertion in the brain. But one insertion has several trajectories associated to it (from various provenance e.g. Planned or Micromanipulator), which is a straight-line set of coordinates.

Q: How to query for insertions / trajectories that are missing alignment?
A: To find insertions that are missing alignment (<2), use:
unresolved = one.alyx.rest('insertions', 'list', django='json__extended_qc__alignment_count__lt,2')

To find trajectories that are missing alignment, use:
unresolved = one.alyx.rest('trajectories', 'list', django='probe_insertion__json__extended_qc__alignment_count__lt,2')
Note the probe_insertion__ addition in the query : this is because the trajectory is linked to the insertion.

Closing this for now.