Equation

A Rust library for mathematical expression evaluation and simplification.

TODO

Rewrite pest parsing as PrattParser;
Modulo % & exponent ** support;
Unary minus operator support;
Support fractions as ~~f32~~ f64;
Support basic triggernomic ratio functions sine, cosine & tangent as sin, cos & tan;
Support functions with additional arguments, atan2(y, x);
Support evaluate steps parameter to break evaluation steps into a Vec<&str>;
Support simplification & evaluation of algebraic expressions;
Support for vectors and basic vector arithmetic & operations;

Getting started

Add the following lines to your Cargo.toml dependencies:

[dependencies]
equation = "1.0.0"

Examples

Evaluate basic arithmetic equations and return a f64.

use equation::evaluate;

fn main() {
    let result = evaluate("(1 + 2) * (1 + 2)"); // Returns Ok(9.0)
    match result {
        Ok(val) => println!("{}", val),
        Err(e) => println!("Error: {:?}", e),
    }
}

Support

Basic arithematic

evaluate("(1 + 2) * 1 + 2"); // Returns Ok(5.0)
evaluate("4 * 3");           // Returns Ok(12.0)
evaluate("8 / 2");           // Returns Ok(4.0)
evaluate("16 - 4");          // Returns Ok(12.0)

Negative calculations

Unary operator. Returns the negation of its operand.

evaluate("-4 * 3"); // Returns Ok(-12.0)
evaluate("-8 / 2"); // Returns Ok(-4.0)
evaluate("-(4 + 4)"); // Returns Ok(-8.0)

Exponentation

Calculates the base to the exponent power, base ^ exponent.

evaluate("2 ^ 8");   // Returns Ok(256.0)
evaluate("2 exp 9"); // Returns Ok(512.0)

Modulus

Returns the integer remainder of dividing the two operands.

evaluate("10 % 2");   // Returns Ok(0.0)
evaluate("10 % 4");   // Returns Ok(2.0)
evaluate("10 mod 3"); // Returns Ok(1.0)

Triggernomic functions

Function	Description	Example	Result
sin	Sine of the input	`evaluate("sin(10.0));`	`Ok(-0.5440211108893698)`
cos	Cosine of the input	`evaluate("cos(10.0));`	`Ok(-0.8390715290764524)`
tan	Tangent of the input	`evaluate("tan(10.0));`	`Ok(0.6483608274590867)`
asin	Inverse sine of the input	`evaluate("asin(0.5));`	`Ok(0.5235987755982988);)`
acos	Inverse cosine of the input	`evaluate("acos(0.5));`	`Ok(1.0471975511965976);)`
atan	Inverse tangent of the input	`evaluate("atan(10.0));`	`Ok(1.4711276743037345);)`
sinh	Hyperbolic sine of the input	`evaluate("sinh(10.0));`	`Ok(11013.232874703393);)`
cosh	Hyperbolic cosine of the input	`evaluate("cosh(10.0));`	`Ok(11013.232920103323);)`
tanh	Hyperbolic tangent of the input	`evaluate("tanh(10.0));`	`Ok(0.9999999958776927);)`
asinh	Inverse hyperbolic sine of the input	`evaluate("asinh(10.0));`	`Ok(2.99822295029797);)`
acosh	Inverse hyperbolic cosine of the input	`evaluate("acosh(10.0));`	`Ok(2.993222846126381);)`
atanh	Inverse hyperbolic tangent of the input	`evaluate("atanh(10.0));`	`Ok(0.5493061443340549);)`

License