CosmoStat / CosmoStat/shapepipe

A/B: azgauss vs fitgauss metacal reconvolution kernel

Open
#830 0 comments 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

Dominant language
Python
Stars
18
Forks
14
Avg merge
8h 40m
Merged PRs (30d)
10

Description

#829 exposes the metacal reconvolution kernel as a config knob (METACAL_PSF), defaulting to the fiducial fitgauss. azgauss (new in ngmix v2.4.1, pinned in #819) is pitched as a noise-robust drop-in replacement — worth an A/B before flipping the default.

Question: does azgauss change recovered m/c bias relative to fitgauss, and is it worth adopting as fiducial?

Mechanism: METACAL_PSF = azgauss vs fitgauss, digital-twin / image-sim comparison (calibrated m/c truth) per #813's methodology, complementary to real-data area once available.

— Claude, on behalf of Cail

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start by reading #813's digital-twin and image-simulation methodology, then inspect the METACAL_PSF configuration from #829. Compare azgauss and fitgauss using calibrated m/c truth, and document whether recovered bias changes enough to justify adopting azgauss as the fiducial.

Written by the indexing model from the issue text.

Assessment

Tech stack
python
Domain
computer-vision
Issue type
Feature
Difficulty
5/5
Estimated time
Over a week
Activity status
Quiet
Clarity
Mostly clear
Newbie friendliness
45/100

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.