changed dir structure a bit II

lib/geo.rb

@@ -0,0 +1,61 @@
+#!/usr/bin/env ruby
+=begin
+    Andrew Turner, ruby distance calculation
+    Copyright (C) 2005 Andrew Turner
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+
+   Please send patches / bug reports to [email protected]
+
+=end
+
+
+class Geo
+  def deg2rad(deg)
+  	(deg * Math::PI / 180)
+  end
+
+  def rad2deg(rad)
+  	(rad * 180 / Math::PI)
+  end
+
+  def abs(x)
+    if x >= 0
+      x
+    else
+      -x
+    end
+  end
+
+  def acos(rad)
+  	Math.atan2(Math.sqrt(abs(1 - rad**2)), rad)
+  end
+
+  def distance_in_km(lat1, lon1, lat2, lon2)
+  	theta = lon1 - lon2
+
+  	dist = Math.sin(self.deg2rad(lat1)) * Math.sin(deg2rad(lat2)) + Math.cos(self.deg2rad(lat1)) * Math.cos(self.deg2rad(lat2)) * Math.cos(deg2rad(theta))
+
+  	dist = self.rad2deg(self.acos(dist))
+
+  	(dist * 60.0 * 1.1515 * 1.609344) #distance in km
+  end
+
+  def distance_in_m(lat1, lon1, lat2, lon2)
+  	distance_in_km(lat1, lon1, lat2, lon2) * 1000
+  end
+
+
+end