sp_validation

Validation of weak-lensing catalogues (galaxy and star shapes and other parameters) produced by ShapePipe.

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Authors: the CosmoStat lab at CEA Paris-Saclay — Martin Kilbinger, Cail Daley, Sacha Guerrini.
Contributors: Emma Ayçoberry, Lucie Baumont, Clara Bonini, Samuel Farrens, Lisa Goh, Axel Guinot, Fabian Hervas Peters.
Contact: martin.kilbinger@cea.fr

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This package contains a library and several scripts and notebooks. The main tasks that can be performed by sp_validation are:

• Shear validation, in particular for the output of the shapepipe pipeline. This task takes on input a shear catalogue with metacal information, performs the calibration and carries out various tests, e.g. PSF leakage. A calibrated shear catalogue is then created on output.
• Post processing. A number of scripts allow further processing of the above output calibrated shear catalogue.
• Cosmology validation. This task uses the calibrated shear catalogue from above to run detailed diagnostics useful for further cosmology analysis, e.g. rho- and tau-statistics, E-/B-mode decomposition. Several catalogues can be compared and useful plots are created.
• Cosmology inference. This task uses the calibrated shear catalogue from a shear validation run and performes cosmology inference using the two-point correlation function.

Repository layout

src/sp_validation/    library code (incl. glass_mock core)
cosmo_val/            validation: code + config        (promoted from notebooks/)
cosmo_inference/      inference: code + config         (cosmosis / cosmocov)
workflow/             ALL analysis — modular Snakemake, multi-person → results/
papers/               final-figure assembly only (PDF, colour, layout)
scripts/              real reduction + runner scripts (catalog builders, masking, glass-mock runners)
scratch/              per-person — ad hoc work + personal workflows (tracked)
results/              analysis products + diagnostic plots (contents gitignored, dir kept)
docs/  tests/  config/

The dividing line is the inputs to a paper figure. Everything up to that point is analysis and lives in workflow/: generic, reusable, modular Snakemake, organized for several people, producing both products and diagnostic plots into a single top-level results/. The figure itself is presentation and lives in papers/<paper>/: final-figure assembly only — PDF, colour, layout — tied to one paper, and free to never touch Snakemake. scratch/<person>/ is personal and ad hoc, tracked because sharing scratch is useful. cosmo_val/ and cosmo_inference/ are the side-by-side code+config homes for the validation and inference stages.

The workflow scales by being modular, not monolithic: Snakemake's module directive imports the shared rules under each run's own config and an output prefix, so runs namespace under results/<name>/ without clobbering one another.

Container Installation (Recommended)

The easiest way to install sp_validation is via a container. Docker images are automatically built and pushed to the GitHub Container Registry (GHCR) on every push to develop. This image can be installed and run on most systems (including clusters) with just a few lines of code.

We recommend running the image with Apptainer (formerly Singularity) which is installed on most HPC clusters. To simply run the image, use the following command:

# build writeable "sandbox" container in the current directory
# ./sp_validation will be a directory that functions like a vm
apptainer build --sandbox sp_validation docker://ghcr.io/cosmostat/sp_validation:develop

# open a shell in the container
apptainer shell --writable sp_validation 
# and confirm that the installation was successful
python -c "import sp_validation"

You can also run the image with Docker:

docker run --rm -it ghcr.io/cosmostat/sp_validation:develop python -c "import sp_validation"

We do not currently build images for Apple Silicon/arm64; however the amd64 images should work on these systems, albeit with reduced performance.

Flow chart

The following flow chart illustrates the steps required to go from ShapePipe output products to calibrated and well-selected galaxy catalogues.

Run shear validation

See the documentation for instructions on how to set up and run sp_validation.

Post processing

The output(s) of one or more shear validation runs can be processed further with post-processing scripts. See here for details.

Cosmology validation

TBD.

Cosmology inference

See the corresponding documentation.