Imported Upstream version 0.7

Author: wadey

PKG-INFO

@@ -1,9 +1,9 @@
 Metadata-Version: 1.0
 Name: python-geohash
-Version: 0.2
-Summary: UNKNOWN
-Home-page: UNKNOWN
-Author: UNKNOWN
+Version: 0.7
+Summary: Fast, accurate python geohashing library
+Home-page: http://code.google.com/p/python-geohash/
+Author: Hiroaki Kawai
 Author-email: UNKNOWN
 License: UNKNOWN
 Description: UNKNOWN

README

@@ -1,6 +1,10 @@
 * python-geohash
 python-geohash is a fast, accurate python geohashing library.
 
+python-geohash 0.3 can create C extension. If you want to use python-geohash
+without C extension, simply copy geohash.py into your system. geohash.py will
+work fine without C extension.
+
 ** LICENSE
 Code is licensed under Apache License 2.0, MIT Licence and NEW BSD License.
 You can choose one of the licences above.

geohash.py

@@ -2,6 +2,11 @@
 """
 Copyright (C) 2009 Hiroaki Kawai <[email protected]>
 """
+try:
+	import _geohash
+except ImportError,e:
+	_geohash = None
+
 __all__ = ['encode','decode','decode_exactly','bbox', 'neighbors', 'expand']
 
 _base32 = '0123456789bcdefghjkmnpqrstuvwxyz'
@@ -32,36 +37,49 @@ def _encode_i2c(lat,lon,lat_length,lon_length):
 		a = lat
 		b = lon
 
+	boost = (0,1,4,5,16,17,20,21)
 	ret = ''
-	while precision>0:
-		c = ((a&4)<<2) + ((b&2)<<2) + ((a&2)<<1) + ((b&1)<<1) + (a&1)
-		ret += _base32[c]
+	for i in range(precision):
+		ret+=_base32[(boost[a&7]+(boost[b&3]<<1))&0x1F]
 		t = a>>3
 		a = b>>2
 		b = t
-		precision-=1
 
 	return ret[::-1]
 
 def encode(latitude, longitude, precision=12):
-	if latitude > 90.0 or latitude < -90.0:
+	if latitude >= 90.0 or latitude < -90.0:
 		raise Exception("invalid latitude.")
 	while longitude < -180.0:
 		longitude += 360.0
 	while longitude >= 180.0:
 		longitude -= 360.0
 
-	lat = (latitude+90.0)/180.0
-	lon = (longitude+180.0)/360.0
+	if _geohash:
+		basecode=_geohash.encode(latitude,longitude)
+		if len(basecode)>precision:
+			return basecode[0:precision]
+		return basecode+'0'*(precision-len(basecode))
+	
+	lat = latitude/180.0
+	lon = longitude/360.0
 
-	lat_length=lon_length=precision*5/2
-	if precision%2==1:
+	xprecision=precision+1
+	lat_length=lon_length=xprecision*5/2
+	if xprecision%2==1:
 		lon_length+=1
 
-	lat = int((1<<lat_length)*lat)
-	lon = int((1<<lon_length)*lon)
+	if lat>0:
+		lat = int((1<<lat_length)*lat)+(1<<(lat_length-1))
+	else:
+		lat = (1<<lat_length-1)-int((1<<lat_length)*(-lat))
+	
+	if lon>0:
+		lon = int((1<<lon_length)*lon)+(1<<(lon_length-1))
+	else:
+		lon = (1<<lon_length-1)-int((1<<lon_length)*(-lon))
 
-	return _encode_i2c(lat,lon,lat_length,lon_length)
+	return _encode_i2c(lat,lon,lat_length,lon_length)[:precision]
 
 def _decode_c2i(hashcode):
 	lon = 0
@@ -97,15 +115,28 @@ def _decode_c2i(hashcode):
 	return (lat,lon,lat_length,lon_length)
 
 def decode(hashcode, delta=False):
+	'''
+	decode a hashcode and get center coordinate, and distance between center and outer border
+	'''
+	if _geohash:
+		(lat,lon,lat_bits,lon_bits) = _geohash.decode(hashcode)
+		latitude_delta = 180.0/(2<<lat_bits)
+		longitude_delta = 360.0/(2<<lon_bits)
+		latitude = lat + latitude_delta
+		longitude = lon + longitude_delta
+		if delta:
+			return latitude,longitude,latitude_delta,longitude_delta
+		return latitude,longitude
+	
 	(lat,lon,lat_length,lon_length) = _decode_c2i(hashcode)
 
 	lat = (lat<<1) + 1
 	lon = (lon<<1) + 1
 	lat_length += 1
 	lon_length += 1
 
-	latitude  = 180.0*lat/(1<<lat_length) - 90.0
-	longitude = 360.0*lon/(1<<lon_length) - 180.0
+	latitude  = 180.0*(lat-(1<<(lat_length-1)))/(1<<lat_length)
+	longitude = 360.0*(lon-(1<<(lon_length-1)))/(1<<lon_length)
 	if delta:
 		latitude_delta  = 180.0/(1<<lat_length)
 		longitude_delta = 360.0/(1<<lon_length)
@@ -119,16 +150,36 @@ def decode_exactly(hashcode):
 ## hashcode operations below
 
 def bbox(hashcode):
-	(lat,lon,lat_length,lon_length) = _decode_c2i(hashcode)
+	'''
+	decode a hashcode and get north, south, east and west border.
+	'''
+	if _geohash:
+		(lat,lon,lat_bits,lon_bits) = _geohash.decode(hashcode)
+		latitude_delta = 180.0/(1<<lat_bits)
+		longitude_delta = 360.0/(1<<lon_bits)
+		return {'s':lat,'w':lon,'n':lat+latitude_delta,'e':lon+longitude_delta}
 
+	(lat,lon,lat_length,lon_length) = _decode_c2i(hashcode)
 	ret={}
-	ret['n'] = 180.0*(lat+1)/(1<<lat_length) - 90.0
-	ret['s'] = 180.0*lat/(1<<lat_length) - 90.0
-	ret['e'] = 360.0*(lon+1)/(1<<lon_length) - 180.0
-	ret['w'] = 360.0*lon/(1<<lon_length) - 180.0
+	if lat_length:
+		ret['n'] = 180.0*(lat+1-(1<<(lat_length-1)))/(1<<lat_length)
+		ret['s'] = 180.0*(lat-(1<<(lat_length-1)))/(1<<lat_length)
+	else: # can't calculate the half with bit shifts (negative shift)
+		ret['n'] = 90.0
+		ret['s'] = -90.0
+	
+	if lon_length:
+		ret['e'] = 360.0*(lon+1-(1<<(lon_length-1)))/(1<<lon_length)
+		ret['w'] = 360.0*(lon-(1<<(lon_length-1)))/(1<<lon_length)
+	else: # can't calculate the half with bit shifts (negative shift)
+		ret['e'] = 180.0
+		ret['w'] = -180.0
+	
 	return ret
 
 def neighbors(hashcode):
+	if _geohash and len(hashcode)<25:
+		return _geohash.neighbors(hashcode)
 	(lat,lon,lat_length,lon_length) = _decode_c2i(hashcode)
 	ret = []
 	tlat = lat

setup.py

@@ -1,5 +1,14 @@
-from distutils.core import setup
+from distutils.core import setup, Extension
+
+c1=Extension('_geohash',
+	sources=['src/geohash.cpp',],
+	define_macros = [('PYTHON_MODULE',1),])
+
 setup(name='python-geohash',
-	version='0.2',
-	py_modules=['geohash','quadtree','jpgrid','jpiarea']
+	version='0.7',
+	description='Fast, accurate python geohashing library',
+	author='Hiroaki Kawai',
+	url='http://code.google.com/p/python-geohash/',
+	py_modules=['geohash','quadtree','jpgrid','jpiarea'],
+	ext_modules = [c1]
 )

src/Makefile

@@ -0,0 +1,16 @@
+CC	= gcc
+CXX	= g++
+CFLAGS	= -O3
+CXXFLAGS	=
+TARGET	= sample
+OBJS	= geohash_sample.o geohash.o
+
+all:	$(TARGET)
+$(TARGET):	$(OBJS)
+	$(CXX) -o $@ $(OBJS)
+clean:
+	-rm -f $(TARGET) $(OBJS)
+.c.o:
+	$(CC) $(CFLAGS) -c $<
+.cpp.o:
+	$(CXX) $(CXXFLAGS) -c $<