Largest Triangle Three Buckets

An implementation of the largest triangle three buckets (lttb) algorithm for time series downsampling as described in Downsampling Time Series for Visual Representation. This is a Rust port of the original Javascript implementation.

Example

``` rust extern crate lttb;

use lttb::{DataPoint,lttb};

let mut raw = vec!(); raw.push(DataPoint::new(0.0, 10.0)); raw.push(DataPoint::new(1.0, 12.0)); raw.push(DataPoint::new(2.0, 8.0)); raw.push(DataPoint::new(3.0, 10.0)); raw.push(DataPoint::new(4.0, 12.0));

// Downsample the raw data to use just three datapoints. let downsampled = lttb(raw, 3); ```