v0.31.0 - Zenith Angle Option for check_event_rate.py (2026-07-02)¶

What Changed?¶

This release adds a --zenith option to check_event_rate.py to record the detector zenith angle alongside event rate summary data. The value is stored in the summary JSON for later analysis of angular dependence.

What's New¶

Main Feature: --zenith Option in check_event_rate.py¶

What it does: Accepts the detector zenith angle in degrees and stores it in the summary JSON file. Useful when taking measurements at multiple angles to study cosmic ray angular dependence.

How to use it:

# Measure at 45 degrees zenith angle
uv run examples/check_event_rate.py ./data --zenith 45 --save

# Vertical (default)
uv run examples/check_event_rate.py ./data --save

Summary JSON (excerpt):

{
  "total": 12345,
  "duration": 3600.0,
  "resample_s": 10,
  "zenith": 45.0,
  ...
}

Installation¶

Quick Start¶

# Get the release
git checkout 0.31.0

# Setup
task env:setup

# Run CLI
uv run kazunoko --help

What's Different from the Last Version?¶

✅ Added¶

• check_event_rate.py: --zenith FLOAT option (default: 0, range: -90 to 90)
• check_event_rate.py: "zenith" field in summary JSON output

Is It Safe to Upgrade?¶

Backward Compatible: Yes

• Default zenith is 0; existing workflows are unchanged

Tests Passed¶

• ✅ Builds without errors
• ✅ uv run check_event_rate.py ./data --zenith 45 --save stores "zenith": 45.0 in JSON

Release Details¶

• Date: 2026-07-02
• Version: v0.31.0
• Files Changed: 1 (check_event_rate.py)