>[!warning]
>This content has not been peer reviewed.
# Constructal Flow — Code
## Purpose
Simulates flow from a hot source to a cold sink on a 2D lattice graph. Landauer pruning removes the lowest-flow edges each step. High-flow edges (on shortest paths and their basin) survive. The result is tree-like (vascular, river-basin) structure emergence.
## Engine
Uses NetworkX for graph operations. No fidelity engine import; flow is computed from shortest-path usage. The Landauer tax is modeled as pruning: low-throughput edges are removed.
## Parameters
| Parameter | Default | Meaning |
|:---|:---|:---|
| `--size` | 15 | Lattice size (size x size) |
| `--steps` | 30 | Pruning iterations |
| `--prune-frac` | 0.08 | Fraction of lowest-flow edges to prune each step |
## Output
| File | Description |
|:---|:---|
| `constructal_flow_emergence.png` | Final graph with source (red) and sink (green) |
## Results
**Results:** [[Constructal Flow Results]]
## Links
- **Application:** [[Constructal Law (RST)]]
- **Knowledge:** [[expanded theory/knowledge/Persisting systems evolve to ease the flow of currents]]