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pray-calc-ml
A Python data science project that compiles human-verified Islamic prayer sighting records and back-calculates solar depression angles. The goal is to find the real empirical patterns in how the Fajr and Isha angles vary with latitude, season, and elevation, then use machine learning to refine the DPC (Dynamic Pray Calc) algorithm in pray-calc.
Pages
- Data Collection — how to run the pipeline, add new sources, and expand the dataset
- ML Crunching — how to run the analysis notebook and train ML models
- Architecture — how the pipeline works, data schema, quality filters
- Data Sources — full citation table for all sighting records in the dataset
- Data — sources log: all sources searched and their current ingestion status
- Research — academic paper summaries and open questions about the data
- Research Notes — detailed per-paper notes and regional analysis
Quick start
git clone https://github.com/acamarata/pray-calc-ml.git
cd pray-calc-ml
python -m venv .venv && source .venv/bin/activate
pip install -r requirements.txt
# Generate datasets (requires network for OpenFajr iCal + elevation API)
python -m src.pipeline
# Or skip the elevation API:
python -m src.pipeline --no-elevation-lookup
Output: data/processed/fajr_angles.csv and data/processed/isha_angles.csv
Current dataset
| Dataset | Records | Locations | Latitude range | Date range |
|---|---|---|---|---|
| Fajr | 5,871 | 110 | -9.6° to 53.8° | 1970-2026 |
| Isha | 46 | 5 | -33.9° to 53.8° | 1985-2022 |
Total: 5,917 unique sighting records across 114 unique locations in 15+ countries.
Target: 100,000 per dataset. Only human-verified observational records are included. Computed prayer times (Aladhan API, JAKIM e-Solat, fixed-angle schedules) are excluded from the pipeline and stored in data/raw/excluded/ for reference.
Key finding
Near-equatorial sites (Malaysia, Indonesia, 2-7°) show mean Fajr angles of 16-17°, while high-latitude sites (Birmingham, UK, 52°N) average ~13°. Seasonality is a significant second factor: at 52°N, the Fajr angle has a ~3° peak-to-trough seasonal swing. Elevation shows a smaller but real positive correlation. Desert sites across Saudi Arabia, Mauritania, and Egypt cluster tightly around 14-15° with low variance (SD ~0.3-0.6°).
The 18° fixed angle commonly used by ISNA and MWL overstates the observed true dawn angle at virtually all well-documented sites.
Part of the acamarata Islamic computing library suite.