diff -r efd9c589177a -r c0b4a8b5a012 toolkit/javascript/d3/src/core/uninterpolate.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/javascript/d3/src/core/uninterpolate.js	Thu Apr 10 14:20:23 2014 +0200
@@ -0,0 +1,9 @@
+function d3_uninterpolateNumber(a, b) {
+  b = b - (a = +a) ? 1 / (b - a) : 0;
+  return function(x) { return (x - a) * b; };
+}
+
+function d3_uninterpolateClamp(a, b) {
+  b = b - (a = +a) ? 1 / (b - a) : 0;
+  return function(x) { return Math.max(0, Math.min(1, (x - a) * b)); };
+}