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Main Author: Julien Boudry
License: MIT - Please say hello if you like or use this code!
Contribute: Contribution File
Donation: ₿ bc1q3jllk3qd9fjvvuqy07tawkv7t6h7qjf55fc2gh or GitHub Sponsor Page
You can also offer me a bottle of good wine.

:ballot_box: Also discover Condorcet Desktop — a graphical app to run elections without any code, also available online at desktop.condorcet.vote

Condorcet PHP<!-- {docsify-ignore-all} -->

Presentation | Documentation Book | API Reference | Voting Methods | Tests

Condorcet is a powerful engine for managing electoral processes and calculating election results. It handles all aspects from configuration and vote collection to result calculation. The library natively implements over 20 voting methods compatible with preferential voting ballots, including Condorcet methods, Alternative Voting, STV, and many others. => See all supported voting methods

Two ways to use Condorcet:

• Command Line Application: For quick access to essential features without technical expertise. Easily compute election results and statistics.
• PHP Library: Integrate into your code to access all advanced features (custom manipulations, extensions, performance optimizations, advanced I/O methods, etc.).

Both approaches can handle massive numbers of votes (hundreds of millions) on modest hardware.

Summary

• Condorcet PHP
  • Project State and Specifications
  • Supported Voting Methods
    • Single-Winner Methods provided natively
      • Deterministic
      • Lotteries
    • Proportional Methods provided natively
    • Add your own voting method as a module
  • Main Features
  • Use Condorcet as a command line application
    • Install as a command line application
    • Condorcet Book - Command Line
  • Use Condorcet as a PHP Library
    • Install / Autoloading
    • Library Manual
    • Class & API References
    • PHP Library - Examples
  • Performance & Coding Style Considerations
    • Coding Standards
    • Performance
  • Roadmap for Further Releases
  • Related projects / They use Condorcet

Project State and Specifications

Release Notes

| Version | PHP Requirements | State | Support | --- | --- | --- | --- | | 5.0 | 8.4 | Stable | ✔ support provided | 4.7 | 8.3 | Old Stable | ✔ support provided | 4.6 | 8.2 | Old Stable | ❌ not any support | 3.x | 8.1 | Old Stable | ❌ not any support | 2.2 | 7.4 | Old Stable | ❌ support requiring some incentive | 2.0 | 7.1 | Old Stable | ❌ not any support | 1.0 | 5.6 | Old Stable | ❌ not any support | 0.9x | 5.5 | Old Stable | ❌ ℹ Since v0.90, you should consider then it's a new project (api, engine). | 0.14 | 5.5 | Old Stable | ❌ ready for the museum

All versions require Json and Mbstring extensions (or polyfill). Pdo-Sqlite is recommended for elections with hundreds of thousands of votes or more.

Supported Voting Methods

Condorcet supports both "single-winner" methods (with full ranking extrapolation) and proportional representation systems.

Full details on voting methods, options, and implementation choices

Single-Winner Methods provided natively

Single-winner methods return a complete ranking of all candidates.

Deterministic

Condorcet / Borda (+ Nauru variant) / Copeland / Dodgson (2 Approximations) / FPTP / Instant-runoff (alternative vote) / Kemeny–Young / Minimax (+ variants) / Ranked Pairs (+ variants) / Schulze (+ variants)

Lotteries

Random Ballot / Random Candidates

Proportional Methods provided natively

Methods designed for electing multiple candidates to an assembly.

Single Transferable Vote (STV) / Comparison of Pairs of Outcomes by the Single Transferable Vote (CPO-STV) / Highest Averages Methods (Sainte-Laguë, Jefferson/D'Hondt, and variants) / Largest Remainder Methods (with different quotas)

Add your own voting method as a module

Condorcet features a modular architecture allowing easy extension with new algorithms:

• Documentation on creating voting methods
• Module Skeleton Template

Main Features

• Complete Election Management

  • Handle the full election cycle: candidate registration, vote collection, result calculation
  • Support for vote ordering, tagging, deletion, and result simulation
  • Multiple input formats (string, JSON, objects)
  • Import/export support for Condorcet Election Format, Debian Format, David Hill Format
  • Integrity verification through checksumming
  • Serialization and data export for storage
  • User-friendly features (vote validation, anti-spam, human-readable results)

• Comprehensive Results and Statistics

  • Identify Condorcet Winners, Losers, and Paradoxes
  • Generate complete rankings using various voting methods
  • Detailed statistical analysis of results
  • Support for both complete and partial ballot rankings
  • Vote weighting capabilities

• Advanced Capabilities

  • Object-oriented design for flexibility and extendability
  • Dynamic candidate and vote management across multiple elections (simulate election easily)
  • External storage drivers for handling massive elections
  • Intelligent caching system (performance optimization)
  • Vote constraints

• Extensibility and Configuration

  • Extend functionality without modifying core code
  • Create custom vote methods, constraints, and storage drivers
  • Extensive configuration options

Although not primarily designed for maximum performance, Condorcet delivers predictable, linear scaling even with very large elections. While not formally certified, comprehensive test coverage ensures reliable results.

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Use Condorcet as a command line application

Install as a command line application

Available installation methods:

• Native installation from source with Composer
• Standalone PHAR executable file
• Docker image (build or pull)

Installation instructions for command line usage

Condorcet Book - Command Line

• Usage Examples
• [Command Reference](https://docs.condorcet.io/book/2.AsComm