Index: node_modules/d3-polygon/src/area.js
===================================================================
--- node_modules/d3-polygon/src/area.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
+++ node_modules/d3-polygon/src/area.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
@@ -0,0 +1,15 @@
+export default function(polygon) {
+  var i = -1,
+      n = polygon.length,
+      a,
+      b = polygon[n - 1],
+      area = 0;
+
+  while (++i < n) {
+    a = b;
+    b = polygon[i];
+    area += a[1] * b[0] - a[0] * b[1];
+  }
+
+  return area / 2;
+}