MeasureIA Documentation
Welcome to the documentation site of MeasureIA, a tool to measure intrinsic alignment correlation functions in hydrodynamic simulations, for both periodic simulation boxes and lightcones. Please feel free to contact me (m.l.vanheukelum@uu.nl) if you have any questions, or create an issue on GitHub.
Pages
- Getting started — what MeasureIA does and when to use the box vs the lightcone
- Installation
- Guides
- Input — the data dictionaries expected on initialisation
- Usage — worked examples for the box and lightcone
- Output — the structure of the output file
- Per-galaxy contributions — resolving the box signal per shape galaxy
- Included simulations — box sizes and cosmologies known to
SimInfo
- Concepts
- Conventions — the shape and sign conventions (incl. the
e1/e2convention) and binning - Estimator definitions — the mathematics of the estimators
- Conventions — the shape and sign conventions (incl. the
- Examples
- Simulation box — a full measurement on a mock box, with its output
- Lightcone — the same for a mock lightcone with randoms
- Validation & performance
- Validation — cross-package validation and how to run it yourself
- Performance — what a run costs, benchmarked against the same external codes
- Roadmap — recently completed and planned developments
The example pages are the two notebooks from examples/, executed when this site is built, so they show a
real measurement and its plots. Each one can be downloaded from the link at the top of its page or opened in
Google Colab (badges on the Usage page) to run without installing anything.
The API Reference (see the navigation sidebar) documents MeasureIABox, MeasureIALightcone and the
supporting classes.
Roadmap
Recently completed:
- Lightcone methods & cross-code validation (against halotools, treecorr and corr_pc)
- Multiprocessing support for the lightcone version (both
wand multipoles) - Optional responsivity factor for the shape calibration
- NumPy 2 support and testing across Python 3.10 – 3.14
- More exhaustive docstrings and internal method docs
- A 1.4x - 1.7x speed-up of the pair-counting kernel, and a benchmark suite (
benchmarks/) measuring MeasureIA against halotools and treecorr
Planned developments include:
- Non-periodic versions of box methods
- e1,e2 input for box methods
- Further speed-up options: the pair loop is still pure Python/NumPy, and the benchmarks show the remaining time is dominated by the KDTree queries and the per-galaxy Python loop
The issues on GitHub are also used as To Do's. Feel free to request features or comment on those already there to let me know you would like them to have a higher priority.
Contributions
Bug reports, feature requests and questions are all welcome as GitHub issues.
See CONTRIBUTING.md for what makes a
bug report easy to act on (measureia.mocks usually reproduces a problem without your data), how feature
requests are prioritised, and the workflow for contributing code. Pull requests that have not been
discussed in an issue beforehand will not be accepted.
Issues carry a priority label. If you would like something that is already listed, comment on it — enough interest is a good reason to raise its priority.
Citation
Please use the CITATION file to cite this package properly. MeasureIA is archived on Zenodo under the DOI 10.5281/zenodo.17252215, which always resolves to the latest released version. If you need to cite the exact version you used, take that version's own DOI from the Zenodo record instead.