From 4682c15a606573fbc815c43c8bc5f33bfd7782f8 Mon Sep 17 00:00:00 2001
From: Pitchaya Boonsarngsuk <2285135b@student.gla.ac.uk>
Date: Tue, 6 Feb 2018 13:30:13 +0000
Subject: [PATCH] Link add API

---
 src/link.js | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/link.js b/src/link.js
index 5773c82..cd979f2 100644
--- a/src/link.js
+++ b/src/link.js
@@ -15,6 +15,7 @@ export default function() {
       nodes,
       stableVelocity = 0,
       stableVeloHandler = null,
+      latestVelocityDiff = 0
       iterations = 1;
 
   function force(alpha) {
@@ -54,6 +55,7 @@ export default function() {
         velocityDiff += Math.abs(Math.hypot(node.vx-node.oldvx, node.vy-node.oldvy));
       }
       velocityDiff /= n*(n-1);
+      latestVelocityDiff = velocityDiff;
 
       if(velocityDiff<stableVelocity){
         stableVeloHandler();
@@ -90,6 +92,10 @@ export default function() {
     return arguments.length ? (distance = typeof _ === "function" ? _ : constant(+_), initializeDistance(), force) : distance;
   };
 
+  force.latestAccel = function () {
+    return latestVelocityDiff;
+  };
+  
   force.onStableVelo = function (_) {
     return arguments.length ? (stableVeloHandler = _, force) : stableVeloHandler;
   };