summedareatable

Generic implementation of summed area tables with Rust

You can find more information about summed area tables on Wikipedia.

http://en.wikipedia.org/wiki/Summedareatable

Basic usage

Dependecies for your cargo.toml

rust [dependencies] summed-area-table = "*" nalgebra = "0.3.0" // check cargo.toml for dependency for newer version

Import the required content.

rust use nalgebra::{DMat}; use summed_area_table::{SummedAreaTableSource, SummedAreaTable};

Creating a summed area table for a 10x10 matrix filled with ones.

rust let src: DMat<usize> = DMat::new_ones(10,10); let table = src.calculate_full_summed_area_table();

Getting the sum of a specific area

rust assert_eq!(100, table.get_sum((0,0),(9,9))); assert_eq!(50, table.get_sum((0,0),(9,4))); assert_eq!(25, table.get_sum((0,0),(4,4)));

Getting the average of a specific area

rust assert_eq!(10, table.get_average((0,0),(9,9))); assert_eq!(10, table.get_average((0,0),(9,4))); assert_eq!(10, table.get_average((0,0),(4,4)));

Custom Data Source

You can implement the SummedAreaTableSourcetrait for your own types if you want them to have the calculate_summed_area_table() method. All you need, is to implement get_values and return a DMat for your data.

This is how the library does it for DMat<usize> type.

rust impl SummedAreaTableSource for DMat<usize>{ fn get_values(&self) -> &DMat<usize> { self } }