From 4d1c0712cf12f8077e0bfa1da45a21f9b9db67fe Mon Sep 17 00:00:00 2001
From: Ryan Hitchman <hitchmanr@gmail.com>
Date: Wed, 25 Feb 2015 14:30:49 -0800
Subject: [PATCH] sankey: fix nodesByBreadth to have proper ordering

d3.nest().key() converts all keys into strings. d3.ascending does not coerce strings into numbers for comparison -- do it ourselves.

This improves relaxation efficiency. Before, it could traverse levels in the wrong orders, taking longer to propagate values up.
---
 sankey/sankey.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sankey/sankey.js b/sankey/sankey.js
index abe137b..ffc8be9 100644
--- a/sankey/sankey.js
+++ b/sankey/sankey.js
@@ -157,7 +157,7 @@ d3.sankey = function() {
   function computeNodeDepths(iterations) {
     var nodesByBreadth = d3.nest()
         .key(function(d) { return d.x; })
-        .sortKeys(d3.ascending)
+        .sortKeys(function(a, b) { return a - b; })
         .entries(nodes)
         .map(function(d) { return d.values; });