# Gaussian Filtering: `gaussfilt`

`gaussfilt` is a `no_std` library that provides Gaussian filter design and application. Filters may be designed by a known sigma or a known cutoff frequency and sample rate. Orders 0 through 3 are supported.

Allocation is required for kernel design, and interfaces are generic on the `num_traits: Float` so there are are crate features for choice of "std" or "libm" support.

Here are a couple provided signatures:
* `design_gaussian_filter1d(sigma, order, truncate) -> alloc::Vec<F>`
* `design_gaussian_sigma_for_cutoff(cutoff, sample_rate) -> F`
* `apply_gaussian_filter(signal: Iterator<F>, kernel: &[F], pad: bool) -> Iterator<F>`

## Example Usage

Choose a desired cutoff, design a filter, filter some data:

```rust
use gaussfilt::*;
let signal = (0..1000).map(|x| x as f32);
let sigma = design_gaussian_sigma_for_cutoff(10., 100.0);
let filter = design_gaussian_filter1d(sigma, 0, 4.0);
let filtered = apply_gaussian_filter1d(signal, &filter, true);
let data = filtered.collect();
```