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https://github.com/rubensworks/rdf-isomorphic.js
Determines if two RDF graphs are isomorphic
https://github.com/rubensworks/rdf-isomorphic.js
graph hacktoberfest isomorphic isomorphism linked-data rdf rdfjs
Last synced: about 2 months ago
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Determines if two RDF graphs are isomorphic
- Host: GitHub
- URL: https://github.com/rubensworks/rdf-isomorphic.js
- Owner: rubensworks
- License: mit
- Created: 2018-08-30T11:49:22.000Z (over 6 years ago)
- Default Branch: master
- Last Pushed: 2024-09-20T12:34:56.000Z (3 months ago)
- Last Synced: 2024-10-15T07:08:51.906Z (2 months ago)
- Topics: graph, hacktoberfest, isomorphic, isomorphism, linked-data, rdf, rdfjs
- Language: TypeScript
- Homepage:
- Size: 359 KB
- Stars: 8
- Watchers: 3
- Forks: 2
- Open Issues: 5
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- License: LICENSE.txt
Awesome Lists containing this project
README
# RDF Isomorphism
[](https://github.com/rubensworks/rdf-isomorphic.js/actions?query=workflow%3ACI)
[](https://coveralls.io/github/rubensworks/rdf-isomorphic.js?branch=master)
[](https://www.npmjs.com/package/rdf-isomorphic)
Determines if two RDF graphs are [isomorphic](https://www.w3.org/TR/rdf11-concepts/#graph-isomorphism),
i.e., if two RDF graphs are equal while ignoring quad order
and ignoring non-equal blank node labels between the graphs.
This package is can be useful within unit/spec tests.
This library accepts [RDFJS](http://rdf.js.org/)-compliant quads.
## Usage
The following examples assume the following imports:
```javascript
import { DataFactory } from "rdf-data-factory"; // External library
import { isomorphic } from "rdf-isomorphic";
const factory = new DataFactory();
```
### Check if two graphs are isomorphic
```javascript
const graphA = [
factory.quad(
factory.blankNode('s1'),
factory.namedNode('p'),
factory.blankNode('o1'),
),
];
const graphB = [
factory.quad(
factory.blankNode('s2'),
factory.namedNode('p'),
factory.blankNode('o2'),
),
];
isomorphic(graphA, graphB); // Outputs true
```
### Check if two graphs are **not** isomorphic
```javascript
const graphA = [
factory.quad(
factory.blankNode('s1'),
factory.namedNode('p1'),
factory.blankNode('o1'),
),
];
const graphB = [
factory.quad(
factory.blankNode('s2'),
factory.namedNode('p2'),
factory.blankNode('o2'),
),
];
isomorphic(graphA, graphB); // Outputs false
```
### Check if two graphs with nested quads are isomorphic
```javascript
const graphA = [
factory.quad(
factory.quad(
factory.blankNode('sInner'),
factory.namedNode('pInner'),
factory.blankNode('o1'),
),
factory.namedNode('pOuter'),
factory.namedNode('oOuter'),
)
];
const graphB = [
factory.quad(
factory.quad(
factory.blankNode('sInner'),
factory.namedNode('pInner'),
factory.blankNode('o2'),
),
factory.namedNode('pOuter'),
factory.namedNode('oOuter'),
)
];
isomorphic(graphA, graphB); // Outputs true
```
## Algorithm
This algorithm is based on the [RDF isomorphism checker in RDF.rb](http://blog.datagraph.org/2010/03/rdf-isomorphism),
which in its turn is based on the algorithm described by [Jeremy Carrol](http://www.hpl.hp.com/techreports/2001/HPL-2001-293.pdf).
In summary, the algorithm generates a hash for each blank node based on the connected resources.
These hashes are then compared between the two given graphs, and a bijection is attempted to be created.
If no such bijection can be found, then the graphs are considered non-isomorphic.
The implementation of this package is inspired by the Ruby [RDF::Isomorphic](https://github.com/ruby-rdf/rdf-Isomorphic) gem.
The algorithm has been adapted to work this nested quads by [Ruben Taelman](http://rubensworks.net/).
## License
This software is written by [Ruben Taelman](http://rubensworks.net/).
This code is released under the [MIT license](http://opensource.org/licenses/MIT).