@julieisbaka/graphjs-extension-sampling

First-party GraphJS extension that registers six data-reduction samplers: LTTB, M4, RDP, LTD, LTOB, and SMA.

Install

npm install @julieisbaka/graphjs @julieisbaka/graphjs-extension-sampling

Usage

import { Graph } from "@julieisbaka/graphjs";
import { samplingPlugin } from "@julieisbaka/graphjs-extension-sampling";

const graph = new Graph("#graph", {
  plugins: [{ plugin: samplingPlugin }],
  sampling: { enabled: true, maxPoints: 500, method: "lttb" }
});

Samplers

| Name | Description | |--------|-------------| | lttb | Largest-Triangle-Three-Buckets — selects the point in each bucket that forms the largest triangle with its neighbours. Best general-purpose visual fidelity. | | m4 | MinMax — preserves the first, last, min-y, and max-y of each bucket. Guarantees spikes and dips are never lost. | | rdp | Ramer–Douglas–Peucker — removes points within a perpendicular-distance tolerance. Best for smooth/geometric series. | | ltd | Largest-Triangle-Dynamic — adaptive variant of LTTB that recalculates bucket sizes at each step for non-uniform data. | | ltob | Largest-Triangle-One-Bucket — simpler/faster LTTB variant using the first point of the next bucket as the triangle anchor. | | sma | Simple Moving Average — replaces each window of points with its mean. Smooths noise at the cost of peak precision. |

Common helpers subpackage

Shared code used by multiple samplers is also exported via the ./common subpackage for composing custom samplers:

import { triangleArea, splitBuckets } from "@julieisbaka/graphjs-extension-sampling/common";

• triangleArea(a, b, c) — area of the triangle formed by three {x, y} points.
• splitBuckets(points, n) — splits a point array into n equal-sized contiguous buckets.