# [−][src]Crate emd

Earth Mover's Distance (EMD)

This is a wrapper around `pyemd`

[1] for computing the EMD (or Wasserstein)
metric.
By default, it uses Euclidean distance as a cost function, but this
can be changed by using the generic distance function `distance_generic()`

.

# Examples

It allows computing the distance between two vectors (e.g., histograms):

extern crate emd; #[macro_use(array)] extern crate ndarray; use emd::*; use ndarray::*; let x = array![0., 1.]; let y = array![5., 3.]; assert_eq!(distance(&x.view(), &y.view()), 3.5);

Or between matrices (e.g., multivariate histograms). Note that in this case the two matrices must have the same number of columns.

extern crate emd; #[macro_use(array)] extern crate ndarray; use emd::*; use ndarray::*; let x = array![[4., 3.], [3., 6.], [2., 3.]]; let y = array![[2., 3.], [1., 3.]]; assert_eq!(distance_multi(&x.view(), &y.view()), 2.035183758487996);

Alternatively, one can compute EMD for matrices (and, by extension,
vectors) with a chosen distance as cost function by using
`distance_generic()`

.

# References

[1] https://github.com/garydoranjr/pyemd

## Functions

distance | Computes the EMD between two vectors. |

distance_generic | Computes the EMD with a desired cost function (i.e., distance). |

distance_multi | Computes the EMD between two matrices. |

euclidean_distance | Returns the Euclidean distance between two vectors of f64 values. |