EvalExpr-JIT

A high-performance mathematical expression evaluator with JIT compilation and automatic differentiation support. Builds on top of evalexpr and Cranelift.

Features

• 🚀 JIT compilation for fast expression evaluation
• 📊 Automatic differentiation (up to any order)
• 🔢 Support for multiple variables
• 🧮 Higher-order partial derivatives
• 💪 Type-safe and memory-safe Rust implementation

This crate is still under development and the API is subject to change. Not all mathematical operations are supported yet.

Installation

Add this to your Cargo.toml:

[dependencies]
evalexpr-jit = "0.1.0"  # Replace with actual version

Quick Start

use evalexpr_jit::Equation;

fn main() -> Result<(), Box<dyn std::error::Error>> {
    // Create a new equation
    let eq = Equation::new("2*x + y^2".to_string())?;
    
    // Evaluate at point (x=1, y=2)
    let result = eq.eval(&[1.0, 2.0]);
    assert_eq!(result, 6.0); // 2*1 + 2^2 = 6
    
    // Compute gradient
    let gradient = eq.gradient(&[1.0, 2.0]);
    assert_eq!(gradient, vec![2.0, 4.0]); // [∂/∂x, ∂/∂y] = [2, 2y]
    
    Ok(())
}

Advanced Usage

Computing Derivatives

use evalexpr_jit::Equation;

let eq = Equation::new("x^2 * y^2".to_string())?;

// Get specific partial derivative
let dx = eq.derivative("x")?;
let values = vec![2.0, 3.0];
let result = dx(values.as_ptr());

// Compute higher-order derivatives
let dxdy = eq.derive_wrt(&["x", "y"])?;
let result = dxdy(values.as_ptr());

// Compute Hessian matrix
let hessian = eq.hessian(&[2.0, 3.0]);

API Reference

Equation

The main struct representing a mathematical equation. Key methods include:

• new(equation_str: String) -> Result<Self, EquationError>
• eval(&self, values: &[f64]) -> f64
• gradient(&self, values: &[f64]) -> Vec<f64>
• hessian(&self, values: &[f64]) -> Vec<Vec<f64>>
• derivative(&self, variable: &str) -> Result<&JITFunction, EquationError>
• derive_wrt(&self, variables: &[&str]) -> Result<JITFunction, EquationError>

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.