rowan

library1.3.2pypypi✓ verified 86d ago

A Python library for performing quaternion operations using NumPy arrays. Provides functions for quaternion creation, normalization, rotation, interpolation, and conversion between quaternions and other rotation representations (e.g., rotation matrices, axis-angle). Current version: 1.3.2, released 2023-04-03. Release cadence is irregular.

ai-ml data

pip install rowan

github ↗package ↗

INSTALL

IMPORT

SIG · ROWAN

rowan

ai-mlpythonv1.3.2

Install

3.8s avg

Import

260ms

Disk

89MB

Pass rate

10/ 10

Env Coverage10 / 10

glibc

3.9–3.13

musl

3.9–3.13

Install & Compatibility

Where this runs

tested against v1.3.2 · 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 0.250s · 89.6MB

glibc

py 3.10–3.95 runs

installs and imports cleanly · install 3.8s · import 0.270s · 86MB

89MB installed

● package 89MB

Code

Verified usage

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

rowan

✓ import rowan

✗ from rowan import *

Importing * pollutes the namespace; prefer explicit functions.

Create a quaternion from axis-angle, rotate a vector, and convert to rotation matrix.

import rowan import numpy as np # Create a quaternion from axis-angle (radians) axis = np.array([0, 0, 1]) angle = np.pi / 2 q = rowan.from_axis_angle(axis, angle) # Rotate a vector v = np.array([1, 0, 0]) v_rot = rowan.rotate(q, v) print(v_rot) # [0, 1, 0] # Convert to rotation matrix R = rowan.to_matrix(q) print(R)

Debug

Known issues

gotcharowan expects inputs as numpy arrays, not lists. Passing plain Python lists may cause unexpected errors or silently produce wrong results.

fix

Always convert lists to np.array before passing to rowan functions.

affects: all

gotchaQuaternion conventions: rowan uses the scalar-first convention (q = [w, x, y, z]). Some other libraries (e.g., scipy) use scalar-last. Mixing conventions will cause incorrect rotations.

fix

When interfacing with other libraries, convert conventions explicitly: for rowan use [w, x, y, z].

affects: all

gotchaThe function `rowan.from_axis_angle` expects the axis to be normalized. If the axis is not unit length, the quaternion will represent a rotation with incorrect angle.

fix

Normalize the axis vector using `axis / np.linalg.norm(axis)` before passing.

affects: all

Errors

Common errors & fixes

AttributeError: module 'rowan' has no attribute 'from_axis_angle'

Older versions of rowan (<1.0?) use different function names, e.g., `rowan.from_axisangle` (no underscore). Check installed version.

fix

Upgrade to latest rowan: `pip install --upgrade rowan` or use the correct old name: `rowan.from_axisangle`.

TypeError: Object arrays are not supported

Input numpy array has dtype=object, often because it contains mixed types or is created from a ragged list.

fix

Ensure array has homogeneous numeric dtype, e.g., `np.array(..., dtype=np.float64)`.

Upgrade

Version history

1.3.2latest on PyPI · released Oct 28, 2024

Audit

Dependencies

numpyrequiredCore dependency; rowan operates on numpy arrays.

Agent activity

19 hits · last 30 days

node

OpenAI (training)

Resources

githubhttps://github.com/glotzerlab/rowan ↗

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