Michael Winter b20f02b60f Fix DCA Hamiltonian: normalize by max instead of sum

- Change normalization from sum to max: visit_count / max^2
- This gives stronger discrimination toward unvisited nodes
- Weight 1 now gives 66.2% coverage (vs 63.6% baseline)
- Rename CLI: --weight-dca -> --weight-dca-voice-movement
- Rename CLI: --weight-hamiltonian -> --weight-dca-hamiltonian
- Restore DCA Hamiltonian display in analysis output
- Update README with new CLI names and factor descriptions

2026-03-15 13:04:00 +01:00

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Compact Sets

A rational theory of harmony based on Michael Winter's theory of conjunct connected sets in harmonic space, combining ideas from Tom Johnson, James Tenney, and Larry Polansky.

Installation

# Activate virtual environment
source venv/bin/activate

# Run
python -m src.io --dims 4 --chord-size 3

CLI Options

Graph Parameters

--dims 4|5|7|8 - Number of prime dimensions (default: 7)
--chord-size 3|4 - Size of chords (default: 3)
--max-path - Maximum path length (default: 50)
--symdiff-min, --symdiff-max - Symmetric difference range (default: 2-2)
--seed - Random seed (default: random)
--cache-dir - Graph cache directory (default: ./cache)
--output-dir - Output directory (default: output)
--rebuild-cache - Force rebuild graph
--no-cache - Disable caching

Voice Leading Constraints (Hard Factors)

These factors eliminate edges that don't meet the criteria.

--voice-crossing - Allow edges where voices cross (default: rejected)
--direct-tuning - Require edges to be directly tunable (default: enabled)

Voice Leading Weights (Soft Factors)

These factors weigh edges without eliminating them. Set weight to 0 to disable.

--weight-melodic - Weight for melodic threshold (default: 1)
--weight-contrary-motion - Weight for contrary motion (default: 0)
--weight-dca-hamiltonian - Weight for DCA Hamiltonian (favors unvisited nodes, default: 1)
--weight-dca-voice-movement - Weight for DCA voice movement (favors voice changes, default: 1)
--weight-target-range - Weight for target register range (default: 1)

Target Range

--target-range - Target range in octaves for rising register (default: disabled)
- When set, enables target_range factor with weight 1
- Use --weight-target-range to adjust the weight

Weight Factor Details

Hard Factors (Eliminate edges)

Direct tuning: If enabled, eliminates edges that are not directly tunable
Voice crossing: If not allowed (default), eliminates edges with voice crossing

Soft Factors (Weigh edges)

Melodic threshold: Penalizes edges with voice movements outside the melodic range
Contrary motion: Boosts edges where some voices move up and others move down
DCA Hamiltonian: Boosts edges to nodes that haven't been visited recently (favors covering new nodes)
DCA Voice Movement: Boosts edges where voices change/move rather than staying on same pitch
Target range: Boosts edges that move toward the target register

Examples

# Basic usage
python -m src.io

# Rising register to 2 octaves
python -m src.io --target-range 2

# Heavy target range, no DCA voice movement
python -m src.io --target-range 2 --weight-target-range 10 --weight-dca-voice-movement 0

# Disable DCA Hamiltonian (allow revisiting nodes freely)
python -m src.io --weight-dca-hamiltonian 0

# Enable voice crossing
python -m src.io --voice-crossing

Legacy

The legacy/ folder contains earlier versions of this code, used to create the musical works published at unboundedpress.org/works/compact_sets_1_3.

Output

Generated files go to output/:

output_chords.json - Chord data
output_chords.txt - Human-readable chords
output_frequencies.txt - Frequencies in Hz
graph_path.json - Hashes of graph nodes visited (for DCA Hamiltonian analysis)

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