CosmoStat / CosmoStat/shapepipe
Keep per-epoch exposure and CCD identity in the final catalog
Nobody has claimed this yet.
- Dominant language
- Python
- Stars
- 18
- Forks
- 14
- Avg merge
- 8h 40m
- Merged PRs (30d)
- 10
Description
The final catalog records how many exposures went into each galaxy's fit (N_EPOCH, NGMIX_N_EPOCH) but not which ones. make_cat.py writes the per-epoch PSF columns by enumeration index and drops the exp_name-ccd_n key that ngmix.py has at fit time, so no CCD, exposure-epoch, or dither-phase split of the shear catalog is possible without rerunning shape measurement.
The Paper II referee asked for exactly such a split of the B-mode null tests; we replied that this information will be recorded for the tomographic catalog.
Add per-epoch exposure ID and CCD number columns — EXP_ID_n, CCD_n for each epoch slot, in the same layout as the existing HSM_*_PSF_n columns — so the catalog supports these splits.
Pointers: src/shapepipe/modules/ngmix_package/ngmix.py:1171-1174 (key available), src/shapepipe/modules/make_cat_package/make_cat.py:602 (key discarded).
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start with the key handling in src/shapepipe/modules/ngmix_package/ngmix.py:1171-1174 and the catalog-writing logic at src/shapepipe/modules/make_cat_package/make_cat.py:602. Preserve the per-epoch exposure ID and CCD number in the final catalog as EXP_ID_n and CCD_n alongside the existing HSM_*_PSF_n columns, then verify each epoch slot retains the expected identity.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- python
- Domain
- data-engineering
- Issue type
- Feature
- Difficulty
- 3/5
- Estimated time
- 1-2 days
- Activity status
- Active
- Clarity
- Clearly specified
- Newbie friendliness
- 78/100