Minkowski distance

[bvenn]

Description

The Minkowski distance or Minkowski metric is a metric in a normed vector space which can be considered as a generalization of both the Euclidean distance and the Manhattan distance. [1]

References

• [1] https://en.wikipedia.org/wiki/Minkowski_distance

Pointers

• the implementation should be located here: https://github.com/fslaborg/FSharp.Stats/blob/developer/src/FSharp.Stats/DistanceMetrics.fs
• within FSharp.Stats.DistanceMetrics, there are specialized modules Vector and Array, that contain the same functionality as the overarching module, but are optimized for high performance. You should first implement a version, that works on two sequences of generic type and if appropriate add optimized versions within DistanceMetrics.Vector and DistanceMetrics.Array.
• if not inferred automatically, you can ensure that the function works on any input collection (float, int), by adding the inline keyword

  let inline minkowski (s1: seq<'a>) (s1: seq<'a>) (p: int) : float =
    //iterate over both collections and determine the Minkowski distance
    //using a single fold function may be sufficient

• optional: add unit tests for sequences of int, float according to this example.
  • don't forget to test negative values within the input sequence, as well as 0. and nan entries
• optional: add proper XML documentation #281
• Of course you can start developing in notebooks/scripts and afterwards we try to incorporate into the library.

Hints (click to expand if you need additional pointers)

- To be able to contribute to this library you'll need - an GitHub account - an IDE like Visual Studio Community or Visual Studio Code - [dotnet 6 sdk](https://dotnet.microsoft.com/en-us/download) - to build the binaries yourself follow the [instructions](https://fslab.org/FSharp.Stats/#Installation) - while working on the [FSharp.Stats documentation](https://fslab.org/FSharp.Stats/) (any file within https://github.com/fslaborg/FSharp.Stats/tree/developer/docs) you can navigate to the project folder with a prompt of your choice and use the command `./build watchdocs` - unit tests can be executed via `./build runtests`

[s-weil]

I will work on this issue

[s-weil]

Hi @bvenn

I would like to open my PR on this issue, but haven't been able to publish my branch yet. Are there any write restrictions in place? Thanks a lot for the help

[bvenn]

Hi @s-weil

first of all: Thank you for your contribution 👍

You have to fork the repo and open a PR from the feature-branch of your fork to the developer branch of fslaborg. I hope that helps. If not, dont hesitate in contacting again.

[s-weil]

Thanks, that helped. the PR is here: https://github.com/fslaborg/FSharp.Stats/pull/308