--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/javascript/d3/src/core/number.js	Thu Apr 10 14:20:23 2014 +0200
@@ -0,0 +1,3 @@
+function d3_number(x) {
+  return x != null && !isNaN(x);
+}