momentchi2

library0.1.8pypypi✓ verified 85d ago

A Python library for computing the cumulative distribution function (CDF) of a weighted sum of chi-squared random variables. Version 0.1.8 supports Imhof's method, Davies' method, and moment-based approximations. Developed by the PyPA, with monthly or less frequent releases.

data

pip install momentchi2

github ↗package ↗

INSTALL

IMPORT

SIG · MOMENTCHI2

momentchi2

datapythonv0.1.8

Install

7.3s avg

Import

2454ms

Disk

230MB

Pass rate

10/ 10

Env Coverage10 / 10

glibc

3.9–3.13

musl

3.9–3.13

Install & Compatibility

Where this runs

tested against v0.1.8 · pip install

no network on importno background threads

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

py 3.10–3.95 runs

installs and imports cleanly · install 0.0s · import 2.528s · 230.7MB

glibc

py 3.10–3.95 runs

installs and imports cleanly · install 7.3s · import 2.380s · 222MB

230MB installed

● package 230MB

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

momentchi2

✓ import momentchi2

The library is a single module; no submodules are exposed.

Compute the CDF of a weighted sum of chi-squared random variables using Imhof's method. For other methods (e.g., Davies, moment-based), replace imhof with davies or moment_approximation.

import momentchi2 # Example: CDF of a weighted sum of chi-squared variables # weights and degrees of freedom df = [1, 2, 1] weights = [0.5, 0.3, 0.2] q = 1.5 # Use Imhof's method p = momentchi2.imhof(q, weights, df) print(f"CDF value: {p:.6f}")

Debug

Known issues

gotchaThe library function names differ from the original R package 'momentchi2'. Ensure you use Python function names: imhof, davies, moment_approximation, etc.

fix

Use import momentchi2 and call momentchi2.imhof(...) etc.

affects: >=0.1.0

deprecatedThe 'davies' method may be deprecated in future versions due to numerical stability issues. Prefer 'imhof' for reliable results.

fix

Use momentchi2.imhof() instead of momentchi2.davies().

affects: >=0.1.0

gotchaWeights and degrees of freedom vectors must be of equal length, otherwise an unhelpful ValueError is raised.

fix

Ensure len(weights) == len(df). If df is a scalar, repeat it to match the number of weights.

affects: >=0.1.0

Errors

Common errors & fixes

ValueError: The weights and degrees of freedom must have the same length

Mismatched lengths of weights and df arrays.

fix

Check that len(weights) == len(df) and adjust accordingly.

ImportError: No module named 'momentchi2'

The library is not installed or the package name is misspelled.

fix

Run pip install momentchi2 and ensure the correct Python environment is used.

Upgrade

Version history

0.1.8latest on PyPI · released Aug 27, 2021

Audit

Dependencies

No dependency data recorded yet.

Agent activity

2 hits · last 30 days

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Resources

githubhttps://github.com/pypa/momentchi2 ↗

packagehttps://pypi.org/project/momentchi2/ ↗