Polynomial

A library for advanced operations with polynomial expressions. This project is based on Morteza Alikhani's Polynomial.Net project. It adds many additional features and has been refactored to follow SOLID principles.

Recent Improvements

This library has been refactored to apply SOLID principles and modern design patterns. See SOLID_IMPROVEMENTS.md for details.

Key Features

• Interface-based design: Uses IPolynomial, ITerm, and other interfaces for better abstraction
• Separation of concerns: Parser, operations, and business logic are separated
• Extensible operations: New operations can be added without modifying existing code
• Factory pattern: PolynomialFactory for cleaner object creation
• Constants: No magic numbers - all constants are centralized
• Improved performance: Better sorting algorithms (O(n log n) instead of O(n²))

Basic Usage

Creating Polynomials

// Traditional way (still supported)
var poly1 = new Poly("3x^2 + 2x - 1");

// Using factory (recommended)
var factory = new PolynomialFactory();
var poly2 = factory.Create("3x^2 + 2x - 1", 0, 10);

Performing Operations

// Integration
var integrated = poly1.Integrate();

// Differentiation
var derivative = poly1.Derivate();

// Calculate value at x
double value = poly1.Calculate(5.0);

// Find roots
var roots = poly1.Roots();

Using Operations Directly

// More testable and follows OCP
var integrationOp = new IntegrationOperation();
var result = integrationOp.Execute(poly1);

var rootFinder = new RootFinder();
var roots = rootFinder.Execute(poly1);

Architecture

The library is now organized into logical namespaces:

• Polynomial.Interfaces: Contracts and abstractions
• Polynomial.Parsers: Parsing logic
• Polynomial.Operations: Mathematical operations
• Polynomial.Factories: Object creation patterns