Index: node_modules/d3-random/src/normal.js
===================================================================
--- node_modules/d3-random/src/normal.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
+++ node_modules/d3-random/src/normal.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
@@ -0,0 +1,28 @@
+import defaultSource from "./defaultSource.js";
+
+export default (function sourceRandomNormal(source) {
+  function randomNormal(mu, sigma) {
+    var x, r;
+    mu = mu == null ? 0 : +mu;
+    sigma = sigma == null ? 1 : +sigma;
+    return function() {
+      var y;
+
+      // If available, use the second previously-generated uniform random.
+      if (x != null) y = x, x = null;
+
+      // Otherwise, generate a new x and y.
+      else do {
+        x = source() * 2 - 1;
+        y = source() * 2 - 1;
+        r = x * x + y * y;
+      } while (!r || r > 1);
+
+      return mu + sigma * y * Math.sqrt(-2 * Math.log(r) / r);
+    };
+  }
+
+  randomNormal.source = sourceRandomNormal;
+
+  return randomNormal;
+})(defaultSource);