#smawk #matrix #optimization #dynamic-programming

smawk

Functions for finding the minimum value in each row of a totally monotone matrix.

1 unstable release

new 0.1.0 Aug 7, 2018

#22 in #optimization

Download history 13/week @ 2018-08-08

4 downloads per month

SMAWK Algorithm in Rust

This crate contains an implementation of the SMAWK algorithm for finding the smallest element per row in a totally monotone matrix.

Usage

Add this to your Cargo.toml:

[dependencies]
smawk = "0.1"

and this to your crate root:

extern crate smawk;

You can now efficiently find row and column minima. Here is an example where we find the column minima:

extern crate ndarray;
extern crate smawk;

use ndarray::arr2;
use smawk::smawk_column_minima;

let matrix = arr2(&[
    [3, 2, 4, 5, 6],
    [2, 1, 3, 3, 4],
    [2, 1, 3, 3, 4],
    [3, 2, 4, 3, 4],
    [4, 3, 2, 1, 1],
]);
let minima = vec![1, 1, 4, 4, 4];
assert_eq!(smawk_column_minima(&matrix), minima);

The minima vector gives the index of the minimum value per column, so minima[0] == 1 since the minimum value in the first column is 2 (row 1). Note that the smallest row index is returned.

Documentation

API documentation

Release History

This is a changelog describing the most important changes per release.

Version 0.1.0 — August 7th, 2018

First release with the classical offline SMAWK algorithm as well as a newer online version where the matrix entries can depend on previously computed column minima.

License

SMAWK can be distributed according to the MIT license. Contributions will be accepted under the same license.

MIT license

Dependencies

Reverse deps