From 110451d6d60a39ecdf6027f13a26fb5449a6f179 Mon Sep 17 00:00:00 2001
From: Al <albarrentine@gmail.com>
Date: Wed, 28 Oct 2015 21:19:35 -0400
Subject: [PATCH] [polygons] Polygon area calculations

---
 scripts/geodata/polygons/area.py | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)
 create mode 100644 scripts/geodata/polygons/area.py

diff --git a/scripts/geodata/polygons/area.py b/scripts/geodata/polygons/area.py
new file mode 100644
index 00000000..460ba614
--- /dev/null
+++ b/scripts/geodata/polygons/area.py
@@ -0,0 +1,26 @@
+import pyproj
+
+from functools import partial
+from shapely.ops import transform
+from shapely.geometry import Polygon
+
+
+def polygon_area(poly):
+    return transform(
+        partial(pyproj.transform,
+                pyproj.Proj(init='EPSG:4326'),
+                pyproj.Proj(proj='aea',
+                            lat1=poly.bounds[1],
+                            lat2=poly.bounds[2],
+                            )
+                ),
+        poly
+    ).area
+
+
+def polygon_bounding_box_area(poly):
+    bbox = poly.bounds
+    p = Polygon([(bbox[0], bbox[3]), (bbox[0], bbox[1]),
+                 (bbox[2], bbox[1]), (bbox[2], bbox[3]),
+                 ])
+    return polygon_area(p)