anacal

AnaCal

Analytic Calibration for Perturbation Estimation from Galaxy Images.

This framework is designed to measure the shear responses of both existing and future shape estimators. Our goal is to develop a suite of analytical shear estimators that can infer shear with sub-percent accuracy while remaining computationally efficient.

To compute shear response, we introduce the concept of pixel shear response---the derivatives of pixel values with respect to applied shear distortions. We then propagate these responses using quintuple numbers, a technique for efficient shear response tracking. For accurate noise bias correction, we adopt a renoising approach that enables analytical treatment of noise effects.

Currently, the framework supports the following analytical shear estimators:

• FPFS: A fixed moments method based on shapelets including analytic correction for selection, detection and noise bias. (see ref1, ref2, ref3, and ref4.)
• NGMIX: Gaussian model fitting. (see ref5)

Installation

Users can clone this repository and install the latest package by

git clone https://github.com/mr-superonion/AnaCal.git
cd AnaCal
# install required softwares
conda install -c conda-forge --file requirements.txt
# install required softwares for unit tests (if necessary)
conda install -c conda-forge --file requirements_test.txt
pip install . --user

or install stable version

pip install anacal

or

conda install -c conda-forge anacal

Examples

Examples can be found here.

Development

Before sending pull request, please make sure that the modified code passed the pytest and flake8 tests. Run the following commands under the root directory for the tests:

flake8
pytest -vv