diff -r 6641e941ef1e -r ff1a9aa48cfd app/django/contrib/gis/measure.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/app/django/contrib/gis/measure.py	Tue Oct 14 16:00:59 2008 +0000
@@ -0,0 +1,329 @@
+# Copyright (c) 2007, Robert Coup <robert.coup@onetrackmind.co.nz>
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without modification,
+# are permitted provided that the following conditions are met:
+#
+#   1. Redistributions of source code must retain the above copyright notice,
+#      this list of conditions and the following disclaimer.
+#
+#   2. Redistributions in binary form must reproduce the above copyright
+#      notice, this list of conditions and the following disclaimer in the
+#      documentation and/or other materials provided with the distribution.
+#
+#   3. Neither the name of Distance nor the names of its contributors may be used
+#      to endorse or promote products derived from this software without
+#      specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+# ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+# ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#
+"""
+Distance and Area objects to allow for sensible and convienient calculation 
+and conversions.
+
+Authors: Robert Coup, Justin Bronn
+
+Inspired by GeoPy (http://exogen.case.edu/projects/geopy/)
+and Geoff Biggs' PhD work on dimensioned units for robotics.
+"""
+__all__ = ['A', 'Area', 'D', 'Distance']
+from decimal import Decimal
+
+class MeasureBase(object):
+    def default_units(self, kwargs):
+        """
+        Return the unit value and the the default units specified
+        from the given keyword arguments dictionary.
+        """
+        val = 0.0
+        for unit, value in kwargs.iteritems():
+            if unit in self.UNITS:
+                val += self.UNITS[unit] * value
+                default_unit = unit
+            elif unit in self.ALIAS:
+                u = self.ALIAS[unit]
+                val += self.UNITS[u] * value
+                default_unit = u
+            else:
+                lower = unit.lower()
+                if lower in self.UNITS:
+                    val += self.UNITS[lower] * value
+                    default_unit = lower
+                elif lower in self.LALIAS:
+                    u = self.LALIAS[lower]
+                    val += self.UNITS[u] * value
+                    default_unit = u
+                else:
+                    raise AttributeError('Unknown unit type: %s' % unit)
+        return val, default_unit
+
+    @classmethod
+    def unit_attname(cls, unit_str):
+        """
+        Retrieves the unit attribute name for the given unit string.  
+        For example, if the given unit string is 'metre', 'm' would be returned.
+        An exception is raised if an attribute cannot be found.
+        """
+        lower = unit_str.lower()
+        if unit_str in cls.UNITS:
+            return unit_str
+        elif lower in cls.UNITS:
+            return lower
+        elif lower in cls.LALIAS:
+            return cls.LALIAS[lower]
+        else:
+            raise Exception('Could not find a unit keyword associated with "%s"' % unit_str)
+
+class Distance(MeasureBase):
+    UNITS = {
+        'chain' : 20.1168,
+        'chain_benoit' : 20.116782,
+        'chain_sears' : 20.1167645,
+        'british_chain_benoit' : 20.1167824944,
+        'british_chain_sears' : 20.1167651216,
+        'british_chain_sears_truncated' : 20.116756,
+        'cm' : 0.01,
+        'british_ft' : 0.304799471539,
+        'british_yd' : 0.914398414616,
+        'clarke_ft' : 0.3047972654,
+        'clarke_link' : 0.201166195164,
+        'fathom' :  1.8288,
+        'ft': 0.3048,
+        'german_m' : 1.0000135965,
+        'gold_coast_ft' : 0.304799710181508,
+        'indian_yd' : 0.914398530744,
+        'inch' : 0.0254,
+        'km': 1000.0,
+        'link' : 0.201168,
+        'link_benoit' : 0.20116782,
+        'link_sears' : 0.20116765,
+        'm': 1.0,
+        'mi': 1609.344,
+        'mm' : 0.001,
+        'nm': 1852.0,
+        'nm_uk' : 1853.184,
+        'rod' : 5.0292,
+        'sears_yd' : 0.91439841,
+        'survey_ft' : 0.304800609601,
+        'um' : 0.000001,
+        'yd': 0.9144,
+        }
+
+    # Unit aliases for `UNIT` terms encountered in Spatial Reference WKT.
+    ALIAS = {
+        'centimeter' : 'cm',
+        'foot' : 'ft',
+        'inches' : 'inch',
+        'kilometer' : 'km',
+        'kilometre' : 'km',
+        'meter' : 'm',
+        'metre' : 'm',
+        'micrometer' : 'um',
+        'micrometre' : 'um',
+        'millimeter' : 'mm',
+        'millimetre' : 'mm',
+        'mile' : 'mi',
+        'yard' : 'yd',
+        'British chain (Benoit 1895 B)' : 'british_chain_benoit',
+        'British chain (Sears 1922)' : 'british_chain_sears',
+        'British chain (Sears 1922 truncated)' : 'british_chain_sears_truncated',
+        'British foot (Sears 1922)' : 'british_ft',
+        'British foot' : 'british_ft',
+        'British yard (Sears 1922)' : 'british_yd',
+        'British yard' : 'british_yd',
+        "Clarke's Foot" : 'clarke_ft',
+        "Clarke's link" : 'clarke_link',
+        'Chain (Benoit)' : 'chain_benoit',
+        'Chain (Sears)' : 'chain_sears',
+        'Foot (International)' : 'ft',
+        'German legal metre' : 'german_m',
+        'Gold Coast foot' : 'gold_coast_ft',
+        'Indian yard' : 'indian_yd',
+        'Link (Benoit)': 'link_benoit',
+        'Link (Sears)': 'link_sears',
+        'Nautical Mile' : 'nm',
+        'Nautical Mile (UK)' : 'nm_uk',
+        'US survey foot' : 'survey_ft',
+        'U.S. Foot' : 'survey_ft',
+        'Yard (Indian)' : 'indian_yd',
+        'Yard (Sears)' : 'sears_yd'
+        }
+    LALIAS = dict([(k.lower(), v) for k, v in ALIAS.items()])
+
+    def __init__(self, default_unit=None, **kwargs):
+        # The base unit is in meters.
+        self.m, self._default_unit = self.default_units(kwargs)
+        if default_unit and isinstance(default_unit, str):
+            self._default_unit = default_unit
+    
+    def __getattr__(self, name):
+        if name in self.UNITS:
+            return self.m / self.UNITS[name]
+        else:
+            raise AttributeError('Unknown unit type: %s' % name)
+    
+    def __repr__(self):
+        return 'Distance(%s=%s)' % (self._default_unit, getattr(self, self._default_unit))
+
+    def __str__(self):
+        return '%s %s' % (getattr(self, self._default_unit), self._default_unit)
+        
+    def __cmp__(self, other):
+        if isinstance(other, Distance):
+            return cmp(self.m, other.m)
+        else:
+            return NotImplemented
+        
+    def __add__(self, other):
+        if isinstance(other, Distance):
+            return Distance(default_unit=self._default_unit, m=(self.m + other.m))
+        else:
+            raise TypeError('Distance must be added with Distance')
+    
+    def __iadd__(self, other):
+        if isinstance(other, Distance):
+            self.m += other.m
+            return self
+        else:
+            raise TypeError('Distance must be added with Distance')
+    
+    def __sub__(self, other):
+        if isinstance(other, Distance):
+            return Distance(default_unit=self._default_unit, m=(self.m - other.m))
+        else:
+            raise TypeError('Distance must be subtracted from Distance')
+    
+    def __isub__(self, other):
+        if isinstance(other, Distance):
+            self.m -= other.m
+            return self
+        else:
+            raise TypeError('Distance must be subtracted from Distance')
+    
+    def __mul__(self, other):
+        if isinstance(other, (int, float, long, Decimal)):
+            return Distance(default_unit=self._default_unit, m=(self.m * float(other)))
+        elif isinstance(other, Distance):
+            return Area(default_unit='sq_' + self._default_unit, sq_m=(self.m * other.m))
+        else:
+            raise TypeError('Distance must be multiplied with number or Distance')
+    
+    def __imul__(self, other):
+        if isinstance(other, (int, float, long, Decimal)):
+            self.m *= float(other)
+            return self
+        else:
+            raise TypeError('Distance must be multiplied with number')
+    
+    def __div__(self, other):
+        if isinstance(other, (int, float, long, Decimal)):
+            return Distance(default_unit=self._default_unit, m=(self.m / float(other)))
+        else:
+            raise TypeError('Distance must be divided with number')
+
+    def __idiv__(self, other):
+        if isinstance(other, (int, float, long, Decimal)):
+            self.m /= float(other)
+            return self
+        else:
+            raise TypeError('Distance must be divided with number')
+
+    def __nonzero__(self):
+        return bool(self.m)
+
+class Area(MeasureBase):
+    # Getting the square units values and the alias dictionary.
+    UNITS = dict([('sq_%s' % k, v ** 2) for k, v in Distance.UNITS.items()])
+    ALIAS = dict([(k, 'sq_%s' % v) for k, v in Distance.ALIAS.items()])
+    LALIAS = dict([(k.lower(), v) for k, v in ALIAS.items()])
+
+    def __init__(self, default_unit=None, **kwargs):
+        self.sq_m, self._default_unit = self.default_units(kwargs)
+        if default_unit and isinstance(default_unit, str):
+            self._default_unit = default_unit
+    
+    def __getattr__(self, name):
+        if name in self.UNITS:
+            return self.sq_m / self.UNITS[name]
+        else:
+            raise AttributeError('Unknown unit type: ' + name)
+    
+    def __repr__(self):
+        return 'Area(%s=%s)' % (self._default_unit, getattr(self, self._default_unit))
+
+    def __str__(self):
+        return '%s %s' % (getattr(self, self._default_unit), self._default_unit)
+
+    def __cmp__(self, other):
+        if isinstance(other, Area):
+            return cmp(self.sq_m, other.sq_m)
+        else:
+            return NotImplemented
+        
+    def __add__(self, other):
+        if isinstance(other, Area):
+            return Area(default_unit=self._default_unit, sq_m=(self.sq_m + other.sq_m))
+        else:
+            raise TypeError('Area must be added with Area')
+    
+    def __iadd__(self, other):
+        if isinstance(other, Area):
+            self.sq_m += other.sq_m
+            return self
+        else:
+            raise TypeError('Area must be added with Area')
+    
+    def __sub__(self, other):
+        if isinstance(other, Area):
+            return Area(default_unit=self._default_unit, sq_m=(self.sq_m - other.sq_m))
+        else:
+            raise TypeError('Area must be subtracted from Area')
+    
+    def __isub__(self, other):
+        if isinstance(other, Area):
+            self.sq_m -= other.sq_m
+            return self
+        else:
+            raise TypeError('Area must be subtracted from Area')
+    
+    def __mul__(self, other):
+        if isinstance(other, (int, float, long, Decimal)):
+            return Area(default_unit=self._default_unit, sq_m=(self.sq_m * float(other)))
+        else:
+            raise TypeError('Area must be multiplied with number')
+    
+    def __imul__(self, other):
+        if isinstance(other, (int, float, long, Decimal)):
+            self.sq_m *= float(other)
+            return self
+        else:
+            raise TypeError('Area must be multiplied with number')
+    
+    def __div__(self, other):
+        if isinstance(other, (int, float, long, Decimal)):
+            return Area(default_unit=self._default_unit, sq_m=(self.sq_m / float(other)))
+        else:
+            raise TypeError('Area must be divided with number')
+
+    def __idiv__(self, other):
+        if isinstance(other, (int, float, long, Decimal)):
+            self.sq_m /= float(other)
+            return self
+        else:
+            raise TypeError('Area must be divided with number')
+
+    def __nonzero__(self):
+        return bool(self.sq_m)
+        
+# Shortcuts
+D = Distance
+A = Area