Option to keep alignments3D/split (random subset) during 3D refinement (feature request)


I have noticed that for every refinement job (I was using NU-refinement, global&local), cryosparc V2 reassigns the alignments3D/split value such that the first half of the particles belonging to one half the second half of the particles belonging to the other half. For some applications, I think it is ideal if the alignments3D/split is consistent throughout data processing. Is this possible that we could have this feature?

I appreciate your help and your attention!


Hi @chenzhao, thanks for reporting. That is indeed the behaviour of most refinement jobs in cryoSPARC. In the new v2.12, in the homogeneous refinement job, you can turn off the option “force re-split” which will preserve the input split of the half-sets. However, the job will complain and fail if the number of particles in each split in the input is different by more than 1, in this case.

Hi @apunjani,

Thanks a lot for your reply! I saw the new option "force re-do GS split’ in the new homogeneous refinement job, but it seems that it is still not an option in NU refinement and local refinement. Is this the case that these refinement jobs do not re-do the GS split?

Thanks a lot,

@chenzhao no problem :slight_smile: you’re right that option is not in NU refinement - which always re-splits the dataset. Local refinement on the other hand does not re-split the dataset. We’ll try to make this beahviour more consistent.