Test Fixtures

.github/CONTRIBUTING.md

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+# Contributing Guidelines
+
+Thank you for your interest in the project. Everything is still a work in progress and
+your assistance/feedback will inform future development!
+
+## Opening an issue
+
+If you find a bug, want a new feature, or anything else, please create an issue.
+Remember to:
+
+- **Be descriptive.**
+  If you are reporting a bug, include instructions on how to replicate it.
+  If you had an installation error, include the exact steps you were trying & details on your system.
+- **Search for relevant issues.**
+  Look through the open (and recently closed) issues to see if others have reported something similar.
+
+## Testing
+
+`glowpython2` is tested on Linux, MacOS and Windows.
+Currently three Python versions are used (stable, latest, and experimental).
+
+The tests are run as a GitHub action, where the source file & instructions are located in [.github/workflows/ci.yml](workflows/ci.yml)
+
+### Installation for running tests
+
+Because `glowpython2` uses meson-python as its build backend, 
+**editable installs (`pip install -e .`) do not work correctly for running the test suite**.
+Data files required by the Fortran backend are not placed where the package expects them.
+Use a regular install instead:
+
+```bash
+pip install .[test]
+```
+
+**After modifying Fortran source**, you must reinstall for changes to take effect:
+
+```bash
+pip install .
+```
+
+### Running tests locally
+
+From the repo root:
+
+```bash
+pytest tests/
+```
+
+You may run an individual test file if the tests are taking too long.
+
+### Test layout
+
+- **`tests/test_examples.py`** — automatically runs every script in `Examples/` as a subprocess smoke test. No maintenance needed; new examples are picked up automatically.
+- **`tests/test_no_precip.py`**, **`test_maxwellian.py`** — structure and physics assertions for the top-level GLOW functions.
+- **`tests/test_iri.py`** — assertions for both `Iri90` and `Iri2020`.
+- **`tests/test_msis.py`** — assertions for both `NrlMsis00` and `NrlMsis21`.
+- **`tests/conftest.py`** — shared fixtures (`sample_time`, `sample_lat`, `sample_lon`).
+
+### Adding or modifying tests
+
+- **New example script**: drop a `.py` file in `Examples/` — it will be picked up by `test_examples.py` automatically.
+- **New assertion test**: add a `test_*.py` file in `tests/`, or add a test function to an existing file. Use the fixtures from `conftest.py` for the standard time/location inputs.
+- **Physics assertions** should check that outputs are physically reasonable (positive densities, sane temperature ranges, expected species present) rather than matching exact numerical values, so tests stay valid across minor model updates.
+
+## Changelog
+
+All notable changes should be recorded in `CHANGELOG.md` before a release is tagged.
+
+**During development:** add entries under the `[Unreleased]` section at the top of `CHANGELOG.md` as you work. Use the appropriate subsection:
+
+- **Added** — new features or capabilities
+- **Changed** — changes to existing behavior
+- **Fixed** — bug fixes
+- **Removed** — removed features or APIs
+- **Deprecated** — features that will be removed in a future release
+
+**At release time:**
+1. Rename `[Unreleased]` to `[x.y.z] - YYYY-MM-DD` matching the version tag you're about to create.
+2. Add a new empty `[Unreleased]` section above it.
+3. Tag the release in git: `git tag vx.y.z`.
+
+**Example entry:**
+
+```markdown
+## [Unreleased]
+### Added
+- Support for custom altitude grids
+
+### Fixed
+- Incorrect electron density below 80 km under certain solar conditions
+```
+
+Do not list every commit — only changes a user of the library would care about. Trivial internal refactors, test updates, and CI fixes can be omitted.

.github/workflows/ci.yml

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+name: CI
+
+on:
+  push:
+    branches: [master, develop]
+  pull_request:
+    branches: [master]
+
+jobs:
+  test:
+    name: Run tests (${{ matrix.os }}, Python ${{ matrix.python-version }})
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, macos-latest, windows-latest]
+        python-version: ["3.11", "3.12", "3.14"]
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Python (Linux/macOS)
+        if: runner.os != 'Windows'
+        uses: actions/setup-python@v5
+        with:
+          python-version: ${{ matrix.python-version }}
+
+      - name: Install gfortran (Linux)
+        if: runner.os == 'Linux'
+        run: sudo apt-get install -y gfortran
+
+      - name: Install gfortran (macOS)
+        if: runner.os == 'macOS'
+        run: brew install gcc
+
+      - name: Set up conda with Python (Windows)
+        if: runner.os == 'Windows'
+        uses: conda-incubator/setup-miniconda@v3
+        with:
+          miniforge-version: latest
+          python-version: ${{ matrix.python-version }}
+
+      - name: Create short temp directory (Windows)
+        if: runner.os == 'Windows'
+        run: New-Item -ItemType Directory -Force -Path C:\T | Out-Null
+
+      - name: Install gfortran + glowpython2 (Windows)
+        if: runner.os == 'Windows'
+        env:
+          TEMP: C:\T
+          TMP: C:\T
+        run: |
+          conda install -c conda-forge gfortran -y
+          conda run --no-capture-output pip install .[test]
+          conda run python -c "import glowpython2; print(glowpython2.__version__)"
+
+      - name: Install (Linux/macOS)
+        if: runner.os != 'Windows'
+        run: pip install .[test]
+
+      - name: Tests (Linux/macOS)
+        if: runner.os != 'Windows'
+        run: python -m pytest tests
+
+      - name: Tests (Windows)
+        # Running all tests on Windows for now...
+        # If the runtime starts getting too long, this can be changed to just one test
+        if: runner.os == 'Windows'
+        run: conda run --no-capture-output python -m pytest tests
+        # run: conda run --no-capture-output python -m pytest tests/test_no_precip.py
+        # ^^ If we just want to run one test

.gitignore

@@ -35,3 +35,4 @@ OLDGLOW/
 # Others
 *.txt
 *.png
+!Examples/*.png

CHANGELOG.md

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+# Changelog
+
+All notable changes to glowpython2 are documented here.
+
+## [Unreleased]
+### Added
+- `CHANGELOG.md` with history migrated from README
+- GitHub Actions CI workflow for Linux, macOS, and Windows
+- Functionality test suite with `pytest`
+
+### Changed
+- `CONTRIBUTING.md` expanded with changelog workflow and guidelines
+- Changelog section removed from `README.md`
+- README install instructions updated for Windows and general clarity
+- `python-dateutil` dependency removed; minimum Python version bumped
+- `pyproject.toml` dependencies tidied
+- Moved files from tests/ to Examples & updates README to use local versions of some images
+
+### Fixed
+- Windows install:
+  - gfortran now recommended to be installed via conda instead of MSYS2
+  - pip forced to use shorter paths to avoid path-length issues
+
+## [0.0.3] - 2026-01-09
+### Changed
+- Dataset structure changed (**breaking**)
+
+### Fixed
+- Version bumped to 0.0.3
+
+## [0.0.1] - 2025-11-01
+### Added
+- Initial release

Examples/IriComparison.py

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+#!/usr/bin/env python
+"""
+Compare IRI-1990 and IRI-2020 ion densities and temperatures.
+"""
+import matplotlib
+import matplotlib.pyplot as plt
+from datetime import datetime, UTC
+
+from glowpython2 import Iri90
+from glowpython2.utils import alt_grid
+from iri20py import Iri2020
+
+matplotlib.rcParams.update({'mathtext.fontset': 'cm'})
+matplotlib.rc('font', **{'family': 'serif', 'serif': ['Times New Roman']})
+
+time = datetime(2015, 12, 13, 10, 0, 0, tzinfo=UTC)
+lat = 42.6
+lon = -71.2
+alt = alt_grid()
+
+_, ds90 = Iri90().evaluate(time=time, lat=lat, lon=lon, alt=alt)
+_, ds20 = Iri2020().evaluate(time=time, lat=lat, lon=lon, alt=alt)
+
+fig, ax = plt.subplots(figsize=(8, 6), dpi=300)
+tax = ax.twiny()
+
+species = ['O+', 'O2+', 'N+', 'NO+']
+descs  = ['O^+', 'O_2^+', 'N^+', 'NO^+']
+colors = ['r', 'g', 'b', 'm']
+lines, labels = [], []
+
+for spec, color, desc in zip(species, colors, descs):
+    l20, = ds20[spec].plot(y='alt_km', ax=ax, color=color)
+    l90, = ds90[spec].plot(y='alt_km', ax=ax, linestyle='--', color=color)
+    lines  += [l20, l90]
+    labels += [f'IRI-20 ${desc}$', f'IRI-90 ${desc}$']
+
+for ds, ls, label_te, label_ti in [
+    (ds20, '-',  'IRI-20 $T_e$', 'IRI-20 $T_i$'),
+    (ds90, '--', 'IRI-90 $T_e$', 'IRI-90 $T_i$'),
+]:
+    l_te, = ds['Te'].plot(y='alt_km', ax=tax, color='k', linestyle=ls)
+    l_ti, = ds['Ti'].plot(y='alt_km', ax=tax, color='c', alpha=0.7, linestyle=ls)
+    lines  += [l_te, l_ti]
+    labels += [label_te, label_ti]
+
+ax.set_title('IRI-90 vs IRI-20')
+ax.set_xscale('log')
+ax.set_xlabel('Number Density [cm$^{-3}$]')
+tax.set_xlabel('Temperature [K]')
+ax.set_xlim(1e-3, None)
+tax.set_xlim(100, None)
+ax.legend(lines, labels, loc='upper left', fontsize='small')
+
+plt.savefig('iri_comparison.png', dpi=300, bbox_inches='tight')
+plt.show()