math_utils_lib 0.4.1

A library providing math utilities such as a parser/evaluator and a LaTeX export to export a history of parsed expressions and solved equations to LaTeX.
Documentation 
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<p align="center">
  <img src="./images/Banner.png" />
</p>


[![crates.io](https://img.shields.io/badge/crates.io-orange?style=for-the-badge&logo=rust)](https://crates.io/crates/math_utils_lib)
[![docs.rs](https://img.shields.io/badge/docs.rs-gray?style=for-the-badge&logo=docs.rs)](https://docs.rs/math_utils_lib/latest/math_utils_lib/)

This repo/crate provides a number of math utilities:

- Parsing and evaluating expressions containing a combination of matrices, vectors and scalars.
- Solving equations and system of equations (both linear and non-linear).
- Exporting a LaTeX document from a collection of parsed and evaluated expressions.

:warning: This repo/crate has not hit 1.0.0 yet, breaking changes are bound to happen!

## Major features

- Parsing and evaluating calculations with matrices, vectors and scalars.
- A recursive parsing implementation allowing for calculations withing matrices and vectors.
- An inbuilt equation solver for solving linear and non-linear systems of equations, accessible through a custom "function".
- An evaluator based on combinatorics for combining multiple results from equations or sqrt with other operations.
- Inbuilt quality of life functions for exporting results to latex.

## Crate features

- high-prec: uses a precision of 13 instead of 8 (will slow down execution).
- row-major: parses matrices in a row major format.
- output: enables dependencies in order to provide rendered PDFs, PNGs and SVGs. (currently broken)
- serde: enables serde::Serialize and serde::Deserialize on most structs and enums.

## Usage

**For usage information concerning the mathematical properties of the evaluator and more examples, please take a look at [the wiki](https://github.com/Waigo01/math_utils_lib/wiki).**

**For programming documentation, please take a look at [docs.rs](https://docs.rs/math_utils_lib/latest/math_utils_lib/).**


## Examples
```rust
let res = quick_eval("3*3", &Context::empty())?.to_vec();
    
assert_eq!(res[0], value!(9));
```

```rust
let x = Variable::new("x", value!(3));
let res = quick_eval("3x", &Context::from_vars(vec![x]))?.to_vec();

assert_eq!(res[0], value!(9));
```

```rust
let res = quick_eval("[[3, 4, 5], [1, 2, 3], [5, 6, 7]]", &Context::empty())?.to_vec();

assert_eq!(res[0], value!(3, 1, 5; 4, 2, 6; 5, 3, 7));
```

```rust
let function = parse("5x^2+2x+x")?;
let function_var = Function::new("f", function, vec!["x"]);

let res = quick_eval("f(5)", &Context::from_funs(vec![function_var]))?.to_vec();

assert_eq!(res[0], value!(140));
```

```rust
let res = quick_eval("eq(x^2=9, x)", &Context::empty())?.round(3).to_vec();
    
assert_eq!(res, vec![value!(-3), value!(3)]);
```

```rust
let equation = "eq(2x+5y+2z=-38, 3x-2y+4z=17, -6x+y-7z=-12, x, y, z)";

let res = quick_eval(equation, &Context::empty())?.round(3).to_vec();

assert_eq!(res, vec![value!(3, -8, -2)]);
```

> [!CAUTION]
> Due to dependency issues output is currently broken!

```rust
let parsed_expr = parse("3*3+6^5")?;
let res = eval(&parsed_expr, &Context::empty())?;

let step = Step::Calc { term: parsed_expr, result: res, variable_save: Some("x".to_string()) };

let png = png_from_latex(step.as_latex_inline(), 200, "#FFFFFF")?;
```

Output:

![For proper render visit github](./images/test.png)

## TODO

- [x] Support for vectors and matrices
- [x] Calculations in vectors and matrices
- [x] Equations as operators -> eval can handle multiple values
- [ ] Complex numbers
- [ ] Possible tensor support
- [ ] Stable API that makes everyone happy (very hard)

## Issues and Contributions

When opening an issue, please specify the following:

- The mathematical expression that causes the issue
- The error (or lack of it), be it a MathLibError or any other kind of error
- The expected behavior

When it comes to contributions, feel free to fork this repo and open pull requests.