def __init__(self, dim, store = None, name = None):
self.dim = dim
self.store = store
self.name = name
if (store != None):
# Make tables on disk
self.forward = store.attach(name + ":forward")
self.by_location = store.attach(name + ":by_location", Spatial.agg_region, None, Spatial.cmp_location)
else:
# In memory only, used dict and table
self.forward = {}
self.by_location = Table(Spatial.agg_region, None, Spatial.cmp_location)
class Spatial(collections.MutableMapping):
def __init__(self, dim, store = None, name = None):
self.dim = dim
self.store = store
self.name = name
if (store != None):
# Make tables on disk
self.forward = store.attach(name + ":forward")
self.by_location = store.attach(name + ":by_location", Spatial.agg_region, None, Spatial.cmp_location)
else:
# In memory only, used dict and table
self.forward = {}
self.by_location = Table(Spatial.agg_region, None, Spatial.cmp_location)
def __contains__(self, key):
return key in self.forward
def __len__(self):
return len(self.forward)
def __getitem__(self, key):
return self.forward[key]
def __setitem__(self, key, value):
# Verify dimensionality of point
if (len(value) != self.dim):
raise ValueError("Tried to insert point of wrong dimensionality")
# If there is and existing point at this key...
if (key in self.forward):
# Get it's location, and remove from location table
old_val = self.forward[key]
del self.by_location[(old_val, key)]
# Add new point to dict and location table
self.forward[key] = value
self.by_location[(value, key)] = (value, value)
def __delitem__(self, key):
# Get location of key (or raise KeyError)
old_val = self.forward[key]
# Delete from map and location table
del self.forward[key]
del self.by_location[(old_val, key)]
def __iter__(self):
return iter(self.forward)
def within(self, p1, p2):
# Verify proper dimensionality
if len(p1) != self.dim or len(p2) != self.dim:
raise ValueError("Invalid dimensionality in 'within'")
# Compute canonical form of bounding box
min_bounds = map(min, p1, p2)
max_bounds = map(max, p1, p2)
box = (min_bounds, max_bounds)
# Get an iterator that will walk over all elements in
# by_location that intersect wit the query box
it = self.by_location.find(lambda v: Spatial.box_intersect(v, box))
# Covert the keys of by_location (loc, key) to straight keys
return imap(lambda k: k[1], it)
# Computes the bounding box that holds both inputs bounding boxs
@staticmethod
def agg_region(box1, box2):
min_bounds = map(min, box1[0], box2[0])
max_bounds = map(max, box1[1], box2[1])
return (min_bounds, max_bounds)
# Determines if two bounding boxes intersect
@staticmethod
def box_intersect(box1, box2):
for i in range(0, len(box1)):
if (box1[0][i] > box2[1][i]): # If the min of box1 > the max of box 2
return False # They don't intersect
if (box2[0][i] > box1[1][i]): # If the min of box2 > the max of box 1
return False # They don't intersect
return True # Otherwise, the do intersect
# Compares by location and then key
@staticmethod
def cmp_location(k1, k2):
# Try to compare by location
r = Hilbert.cmp(k1[0], k2[0])
# If identical, fall back to key
if r == 0:
r = cmp(k1[1], k2[1])
return r
