diff options
Diffstat (limited to 'src/lp.rs')
| -rw-r--r-- | src/lp.rs | 19 |
1 files changed, 16 insertions, 3 deletions
@@ -1,6 +1,10 @@ -//! [`$L^p$` spaces](https://en.wikipedia.org/wiki/Lp_space). +//! [`$\ell^p$`]/[Minkowski] distance. +//! +//! [`$\ell^p$`]: https://en.wikipedia.org/wiki/Lp_space +//! [Minkowski]: https://en.wikipedia.org/wiki/Minkowski_distance use crate::coords::Coordinates; +use crate::distance::Proximity; use num_traits::real::Real; use num_traits::zero; @@ -25,7 +29,7 @@ pub use crate::chebyshev::Chebyshev as Linf; /// Compute the L<sup>∞</sup> distance between two points. pub use crate::chebyshev::chebyshev_distance as linf_distance; -/// Compute the [`$L^p$` distance] between two points. +/// Compute the [`$\ell^p$`]/[Minkowski] distance between two points. /// /// ```math /// \begin{aligned} @@ -34,7 +38,8 @@ pub use crate::chebyshev::chebyshev_distance as linf_distance; /// \end{aligned} /// ``` /// -/// [`$L^p$` distance]: https://en.wikipedia.org/wiki/Lp_space +/// [`$\ell^p$`]: https://en.wikipedia.org/wiki/Lp_space +/// [Minkowski]: https://en.wikipedia.org/wiki/Minkowski_distance pub fn lp_distance<T, U>(p: T::Value, x: T, y: U) -> T::Value where T: Coordinates, @@ -51,6 +56,14 @@ where sum.powf(p.recip()) } +/// Marker trait for [Minkowski distances]. +/// +/// [Minkowski distances]: https://en.wikipedia.org/wiki/Minkowski_distance +pub trait Minkowski<T: ?Sized = Self>: Proximity<T> {} + +/// Blanket [`Minkowski`] implementation for references. +impl<'k, 'v, K: Minkowski<V>, V> Minkowski<&'v V> for &'k K {} + #[cfg(test)] mod tests { use super::*; |