# hgr-format

> Parses and validates HMETIS hypergraph (.hgr) files. Supports unweighted, edge-weighted, node-weighted, and dually-weighted formats. Use when working with hypergraph partitioning, HMETIS files, or graph partitioning tasks.

- Author: Magi Chen
- Repository: gradinnovate-labs/EDA-Skills
- Version: 20260124164857
- Stars: 0
- Forks: 0
- Last Updated: 2026-02-08
- Source: https://github.com/gradinnovate-labs/EDA-Skills
- Web: https://mule.run/skillshub/@@gradinnovate-labs/EDA-Skills~hgr-format:20260124164857

---

---
name: hgr-format
description: Parses and validates HMETIS hypergraph (.hgr) files. Supports unweighted, edge-weighted, node-weighted, and dually-weighted formats. Use when working with hypergraph partitioning, HMETIS files, or graph partitioning tasks.
license: MIT
compatibility: Requires Python 3.6+
metadata:
  version: "1.0"
  author: gradinnovate-labs
---

# What I do

- **Identify Format Type**: Detect the `fmt` code in the header to determine if the hypergraph uses weights for edges, nodes, or both.
- **Validate Structure**: Verify that the number of lines in the file matches the expected count based on the number of hyperedges ($|E|$) and vertices ($|V|$).
- **Analyze Hypergraph Metadata**: Extract the count of vertices and hyperedges and confirm if weights are present.

## Usage

### Quick Parse

Use the provided script to parse any `.hgr` file:

```bash
python scripts/parse_hgr.py <filename.hgr>
```

**Output:**
- `number nodes`: Total number of vertices ($|V|$)
- `number hyperedges`: Total number of hyperedges ($|E|$)
- `is weighted hyperedges`: Whether hyperedges have weights (true/false)
- `is weighted nodes`: Whether vertices have weights (true/false)
- `is valid hgr`: Whether file structure is valid (true/false)

### Example

```bash
$ python scripts/parse_hgr.py s13207P.hgr
number nodes: 8772
number hyperedges: 8651
is weighted hyperedges: False
is weighted nodes: False
is valid hgr: True
```

## When to use

Use this skill when:
- You need to process HMETIS hypergraph files
- You need to validate hypergraph file structure
- User mentions `.hgr` files, hypergraph partitioning, or HMETIS
- You need to understand hypergraph metadata (nodes, hyperedges, weights)

## Format Overview

HMETIS `.hgr` files support four formats:

| Format Code | Description |
|-------------|-------------|
| (omitted)   | Unweighted (edges and vertices = 1) |
| 1           | Weighted hyperedges |
| 10          | Weighted vertices |
| 11          | Weighted hyperedges and vertices |

See [references/REFERENCE.md](references/REFERENCE.md) for detailed format specifications.

## File Structure

```
hgr-format/
├── SKILL.md              # This file
├── scripts/
│   └── parse_hgr.py      # Main parsing script
├── references/
│   └── REFERENCE.md      # Detailed HMETIS format spec
└── assets/
    └── example.hgr       # Example hypergraph file
```