# Contributing to polyfit
Thank you for considering contributing to polyfit! Please read the following guidelines before you begin
## How to Contribute
1. All new functionality should be covered by tests
2. New features should include examples in the `examples/` directory
3. Consider also updating the tutorials on [https://github.com/rscarson/polyfit-docs]
## API Guidelines
The API is written with the following principles in mind:
### Don't ask the user for a numeric parameter without context
If you ask for a random number, you'll get a random number. Instead, provide contextual clues.
For examples, see `DegreeBound`, or `CvStrategy`.
### Never ask the user for a parameter where you can find an objectively best choice
If there is an objectively best choice for a parameter, use that choice internally, and provide an advanced API for users who want to override it.
For example, see how `k` is chosen in `Polynomial::spectral_energy_filter`.
### The user should not need to understand the how to use the library
- All formulas and algorithms used should be explained in a `Technical Details` section of the docblock
- Examples should be provided for all public functions and methods
- All functions should include a brief 'why' of what it's useful for, and when to avoid using it
- Documentation and names alone should be sufficient to allow a user with 0 mathematical background to use the library effectively
## Code Style
- Follow Rust's standard formatting (`cargo fmt`)
- keep the readme up to date with any changes (`cargo rdme`)
## Reporting Issues
- Use the issue tracker to report bugs or request features.
- Provide as much detail as possible.
Thank you for helping improve polyfit!