fnir 0.1.0

Fast numerical integration rules, like tanh-sinh quadrature
Documentation 
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# Fast Numeric Integration in Rust (FNIR) ![build status](https://github.com/TileHalo/fnir/actions/workflows/rust.yml/badge.svg)
FNIR provides various numerical integration algorithms for use.

## Usage
Add the following under `[dependencies]` in your cargo.toml
```toml
fnir = 0.1.0
```

To use for example the [Michalski-Mosig variant](http://dx.doi.org/10.1080/09205071.2015.1129915)
of $\tanh\sinh$ quadrature include the following:
```rust
use fnir::{Integral, quadrature::{TanhSinh}};
...

let integrator = TanhSinh::new();
let func = |x: f64| f64::powi(x, 2);

let result = integrator.integrate(func, Some(0), Some(1)); // Ok(0.3333...)
```

WARNING: This project is in early stages and until 1.0.0 subject to breaking
chances etc.

## Use cases
This crate can be used to integrate integrals in the form $\int_a^b f(x) dx$
where $a, b \in \R$ and $f: \R \to B \subset \C$, semi-infinite integrals where
either $a$ or $b$ is infinite and infinite intervals (both are infinite).

Currently used and planned quadratures are:
 - [x] Trapezoidal rule
 - [x] Michalski-Mosig $\tanh\sinh$
 - [x] Michalski-Mosig $\exp\sinh$ (semi-infinite interval)
 - [x] Michalski-Mosig $\sinh\sinh$ (infinite interval)

Planned future features include the following:
 - [ ] Complex contour integrals
 - [ ] Integrals over triangular surfaces
 - [ ] Element-wise integration of $N$-dimensional arrays

In some distant future the following would also be nice:
 - [ ] Vectorization (i.e. SIMD)
 - [ ] Generic parametrization

## Contributing
Feel free to submit bug reports, feature requests, and the best of all,
pull requests to those issues.