From 99e634aaba1a915aaff4e94c4233024a4f1db694 Mon Sep 17 00:00:00 2001
From: Al <albarrentine@gmail.com>
Date: Fri, 29 Apr 2016 19:59:53 -0400
Subject: [PATCH] [fix] some weirdness with the dateline and polygons that have
 a longitude of exactly 180.0

---
 scripts/geodata/math/floats.py          | 5 +++++
 scripts/geodata/math/sampling.py        | 6 +-----
 scripts/geodata/osm/admin_boundaries.py | 5 +++++
 3 files changed, 11 insertions(+), 5 deletions(-)
 create mode 100644 scripts/geodata/math/floats.py

diff --git a/scripts/geodata/math/floats.py b/scripts/geodata/math/floats.py
new file mode 100644
index 00000000..1051e332
--- /dev/null
+++ b/scripts/geodata/math/floats.py
@@ -0,0 +1,5 @@
+FLOAT_EPSILON = 1e-09
+
+
+def isclose(a, b, rel_tol=FLOAT_EPSILON, abs_tol=0.0):
+    return abs(a - b) <= max(rel_tol * max(abs(a), abs(b)), abs_tol)
diff --git a/scripts/geodata/math/sampling.py b/scripts/geodata/math/sampling.py
index a0278464..33b94004 100644
--- a/scripts/geodata/math/sampling.py
+++ b/scripts/geodata/math/sampling.py
@@ -2,7 +2,7 @@ import bisect
 import random
 import sys
 
-FLOAT_EPSILON = 1e-09
+from geodata.math.floats import isclose, FLOAT_EPSILON
 
 
 def weighted_choice(values, cdf):
@@ -16,10 +16,6 @@ def weighted_choice(values, cdf):
     return values[i]
 
 
-def isclose(a, b, rel_tol=FLOAT_EPSILON, abs_tol=0.0):
-    return abs(a - b) <= max(rel_tol * max(abs(a), abs(b)), abs_tol)
-
-
 def check_probability_distribution(probs):
     cumulative = 0.0
     for p in probs:
diff --git a/scripts/geodata/osm/admin_boundaries.py b/scripts/geodata/osm/admin_boundaries.py
index 4be5142a..2e9a349d 100644
--- a/scripts/geodata/osm/admin_boundaries.py
+++ b/scripts/geodata/osm/admin_boundaries.py
@@ -15,6 +15,7 @@ from itertools import izip, combinations
 
 from geodata.coordinates.conversion import latlon_to_decimal
 from geodata.graph.scc import strongly_connected_components
+from geodata.math.floats import isclose
 from geodata.osm.extract import *
 
 
@@ -179,6 +180,10 @@ class OSMPolygonReader(object):
                 lat, lon = latlon_to_decimal(lat, lon)
                 if lat is None or lon is None:
                     continue
+
+                if isclose(lon, 180.0):
+                    lon = 179.999
+
                 # Nodes are stored in a sorted array, coordinate indices are simply
                 # [lon, lat, lon, lat ...] so the index can be calculated as 2 * i
                 # Note that the pairs are lon, lat instead of lat, lon for geometry purposes