3ptWL-cov

3ptWL-cov computes the Gaussian contribution to weak-lensing three-point covariance terms in a harmonic basis on the sphere under the Limber approximation. The repository provides a C command-line executable, a static library, a Cython wrapper (wlcovpy), and small Python examples.

Documentation: 3ptWL-cov documentation

Authors

• Sofia Samario-Nava
  ssamario@icf.unam.mx
• Alejandro Aviles
  aviles@icf.unam.mx

Contributors

• Sadi Ramirez Solano - sadi@icf.unam.mx
• Mario A. Rodriguez-Meza - marioalberto.rodriguezmeza@gmail.com

Install with pip

Install the GSL development library first. On Debian or Ubuntu:

sudo apt-get install build-essential libgsl-dev

Then install the Python interface from PyPI:

python3 -m pip install wlcovpy

This installs the wlcovpy module and compiles its native extension; no separate make command is needed. To install the unreleased development version, use python3 -m pip install "git+https://github.com/sadirs/3ptWL-cov.git". From an existing source checkout, use python3 -m pip install .. The standalone wlcov command-line executable is built separately with make, as described below.

Native C build (optional)

Build the standalone executable and static library from a source checkout:

make clean
make PYTHON=python3 all

The Makefile uses gsl-config by default. For a custom GSL installation:

make PYTHON=python3 GSL_INCLUDE=/path/to/gsl/include GSL_LIB=/path/to/gsl/lib all

Native build artifacts:

• wlcov: command-line executable
• libwlcov.a: static C library
• wlcovpy: Cython extension installed by pip install .

Native CLI quick run

./wlcov clsfile=tests/input/Cls_ep2.txt rootDir=Output_quick \
   r=0.01 theta1=0.01 theta2=0.012 thetap1=0.011 thetap2=0.013 \
   m=0 mp=0 ellmin=1 ellmax=25 ppp=4 Nr=8 rmin=0.00232711 rmax=0.02 \
   verbose=0 verbose_log=0

The main input table is supplied with clsfile and must contain two columns: ell and C_ell.

Python Wrapper

from wlcovpy import wlcov

model = wlcov(default=False)
model.set({
    "clsfile": "tests/input/Cls_ep2.txt",
    "rootDir": "Output_python",
    "r": 0.01,
    "theta1": 0.01,
    "theta2": 0.012,
    "thetap1": 0.011,
    "thetap2": 0.013,
    "m": 0,
    "mp": 0,
    "ppp": 4,
    "ellmin": 1.0,
    "ellmax": 25.0,
    "Nr": 8,
    "rmin": 0.00232711,
    "rmax": 0.02,
    "numberThreads": 1,
    "verbose": 0,
    "verbose_log": 0,
    "options": "",
})
try:
    model.Run()
    integral = model.getIntegral()
finally:
    model.clean_all()

See docs/examples/python_wrapper.py, tests/python/, and the main notebook example in tests/notebooks/example.ipynb for runnable examples. The notebook saves its figures in tests/notebooks/plots/.

Documentation

The documentation is built with Sphinx:

python3 -m pip install --user -r docs/requirements.txt
cd docs
make html
make man
make latexpdf

Generated outputs:

• docs/_build/html/index.html
• docs/_build/man/wlcov.1
• docs/_build/latex/3ptWL-cov.pdf

Configuration

Main build switches live in Makefile_settings:

• USEGSL = 1: required for current GSL Bessel routines
• OPENMPMACHINE = 0: set to 1 for OpenMP builds
• ADDONSON = 1: required for the current wrapper path

Addon switches live in addons/Makefile_addons_settings:

• CLASSLIBON = 1
• PXDON = 1
• COSMOLIBON = 0 by default

Citation

If you use this program in research that results in publications, please cite Sofia Samario et al., arXiv:2506.19811, and record the code version, compiler, GSL version, Python environment, and runtime configuration used for the analysis.

License

3ptWL-cov is distributed under the MIT license. See LICENSE.