def __init__(self, shapefile, distance_metric=EUCLIDEAN_DISTANCE):
if issubclass(type(shapefile), basestring): #Path
self.shp = shp = pysal.open(shapefile, 'r')
else:
raise TypeError, "Expecting a string, shapefile should the path to shapefile"
if shp.type != pysal.cg.shapes.Chain:
raise ValueError, "Shapefile must contain polyline features"
self.dbf = dbf = pysal.open(shapefile[:-4] + '.dbf', 'r')
header = dbf.header
if (('FNODE' not in header) or ('TNODE' not in header)
or ('ONEWAY' not in header)):
raise ValueError, "DBF must contain: FNODE,TNODE,ONEWAY"
oneway = [{'F': False, 'T': True}[x] for x in dbf.by_col('ONEWAY')]
fnode = dbf.by_col('FNODE')
tnode = dbf.by_col('TNODE')
if distance_metric == EUCLIDEAN_DISTANCE:
lengths = [x.len for x in shp]
elif distance_metric == ARC_DISTANCE:
lengths = [x.arclen for x in shp]
else:
raise ValueError, "distance_metric must be either EUCLIDEAN_DISTANCE or ARC_DISTANCE"
self.lengths = lengths
if any(oneway):
G = networkx.MultiDiGraph()
#def isoneway(x):
# return x[-1]
#def isnotoneway(x):
# if(x[-1]):
# return False
# return True
#
#A = filter(isoneway,zip(fnode,tnode,oneway))
#B = filter(isnotoneway,zip(fnode,tnode,oneway))
#C = filter(isnotoneway,zip(tnode,fnode,oneway))
#G.add_edges_from(A)
#G.add_edges_from(B)
#G.add_edges_from(C)
else:
G = networkx.MultiGraph()
#zip(fnode,tnode))
self.G = G
shp.seek(0)
self._locator = Polyline_Shapefile_SegmentLocator(shp)
def __init__(self,shapefile,distance_metric=EUCLIDEAN_DISTANCE):
if issubclass(type(shapefile),basestring): #Path
self.shp = shp = pysal.open(shapefile,'r')
else:
raise TypeError,"Expecting a string, shapefile should the path to shapefile"
if shp.type != pysal.cg.shapes.Chain:
raise ValueError,"Shapefile must contain polyline features"
self.dbf = dbf = pysal.open(shapefile[:-4]+'.dbf','r')
header = dbf.header
if (('FNODE' not in header) or ('TNODE' not in header) or ('ONEWAY' not in header)):
raise ValueError,"DBF must contain: FNODE,TNODE,ONEWAY"
oneway = [{'F':False,'T':True}[x] for x in dbf.by_col('ONEWAY')]
fnode = dbf.by_col('FNODE')
tnode = dbf.by_col('TNODE')
if distance_metric == EUCLIDEAN_DISTANCE:
lengths = [x.len for x in shp]
elif distance_metric == ARC_DISTANCE:
lengths = [x.arclen for x in shp]
else:
raise ValueError,"distance_metric must be either EUCLIDEAN_DISTANCE or ARC_DISTANCE"
self.lengths = lengths
if any(oneway):
G = networkx.MultiDiGraph()
#def isoneway(x):
# return x[-1]
#def isnotoneway(x):
# if(x[-1]):
# return False
# return True
#
#A = filter(isoneway,zip(fnode,tnode,oneway))
#B = filter(isnotoneway,zip(fnode,tnode,oneway))
#C = filter(isnotoneway,zip(tnode,fnode,oneway))
#G.add_edges_from(A)
#G.add_edges_from(B)
#G.add_edges_from(C)
else:
G = networkx.MultiGraph()
#zip(fnode,tnode))
self.G = G
shp.seek(0)
self._locator = Polyline_Shapefile_SegmentLocator(shp)
class SpatialNetwork(object):
"""
SpatialNetwork -- Represents a Spatial Network.
A Spatial Network in PySAL is a graph who's nodes and edges are represented by geographic features
such as Points for nodes and Lines for edges.
An example of a spatial network is a road network.
Arguments
---------
shapefile -- Shapefile contains the geographic represention of the network.
The shapefile must be a polyline type and the associated DBF MUST contain the following fields:
FNODE -- source node -- ID of the source node, the first vertex in the polyline feature.
TNODE -- destination node -- ID of the destination node, the last vertex in the polyline feature.
ONEWAY -- bool -- If True, the edge will be marked oneway starting at FNODE and ending at TNODE
distance_metric -- EUCLIDEAN_DISTANCE or ARC_DISTANCE
"""
def __init__(self,shapefile,distance_metric=EUCLIDEAN_DISTANCE):
if issubclass(type(shapefile),basestring): #Path
self.shp = shp = pysal.open(shapefile,'r')
else:
raise TypeError,"Expecting a string, shapefile should the path to shapefile"
if shp.type != pysal.cg.shapes.Chain:
raise ValueError,"Shapefile must contain polyline features"
self.dbf = dbf = pysal.open(shapefile[:-4]+'.dbf','r')
header = dbf.header
if (('FNODE' not in header) or ('TNODE' not in header) or ('ONEWAY' not in header)):
raise ValueError,"DBF must contain: FNODE,TNODE,ONEWAY"
oneway = [{'F':False,'T':True}[x] for x in dbf.by_col('ONEWAY')]
fnode = dbf.by_col('FNODE')
tnode = dbf.by_col('TNODE')
if distance_metric == EUCLIDEAN_DISTANCE:
lengths = [x.len for x in shp]
elif distance_metric == ARC_DISTANCE:
lengths = [x.arclen for x in shp]
else:
raise ValueError,"distance_metric must be either EUCLIDEAN_DISTANCE or ARC_DISTANCE"
self.lengths = lengths
if any(oneway):
G = networkx.MultiDiGraph()
#def isoneway(x):
# return x[-1]
#def isnotoneway(x):
# if(x[-1]):
# return False
# return True
#
#A = filter(isoneway,zip(fnode,tnode,oneway))
#B = filter(isnotoneway,zip(fnode,tnode,oneway))
#C = filter(isnotoneway,zip(tnode,fnode,oneway))
#G.add_edges_from(A)
#G.add_edges_from(B)
#G.add_edges_from(C)
else:
G = networkx.MultiGraph()
#zip(fnode,tnode))
self.G = G
shp.seek(0)
self._locator = Polyline_Shapefile_SegmentLocator(shp)
def snap(self,pt):
i,p,j = self._locator.nearest(pt) #shpID,partID,segmentID
segment = self.shp[i].segments[p][j] #grab segment
d,pct = pysal.cg.get_segment_point_dist(segment,pt) #find pct along segment
x0,x1 = segment.p1[0],segment.p2[0]
x2 = x0 + (x1-x0)*pct # find x location of snap
y2 = segment.line.y(x2) # find y location of snap
#dbf = self.dbf
#rec = dict(zip(dbf.header,dbf[i][0]))
#edge = (rec['FNODE'],rec['TNODE'])
#TODO: Calculate location along edge and distance to edge"
#return edge
return x2,y2
class SpatialNetwork(object):
"""
SpatialNetwork -- Represents a Spatial Network.
A Spatial Network in PySAL is a graph who's nodes and edges are represented by geographic features
such as Points for nodes and Lines for edges.
An example of a spatial network is a road network.
Arguments
---------
shapefile -- Shapefile contains the geographic represention of the network.
The shapefile must be a polyline type and the associated DBF MUST contain the following fields:
FNODE -- source node -- ID of the source node, the first vertex in the polyline feature.
TNODE -- destination node -- ID of the destination node, the last vertex in the polyline feature.
ONEWAY -- bool -- If True, the edge will be marked oneway starting at FNODE and ending at TNODE
distance_metric -- EUCLIDEAN_DISTANCE or ARC_DISTANCE
"""
def __init__(self,shapefile,distance_metric=EUCLIDEAN_DISTANCE):
if issubclass(type(shapefile),str): #Path
self.shp = shp = pysal.open(shapefile,'r')
else:
raise TypeError("Expecting a string, shapefile should the path to shapefile")
if shp.type != pysal.cg.shapes.Chain:
raise ValueError("Shapefile must contain polyline features")
self.dbf = dbf = pysal.open(shapefile[:-4]+'.dbf','r')
header = dbf.header
if (('FNODE' not in header) or ('TNODE' not in header) or ('ONEWAY' not in header)):
raise ValueError("DBF must contain: FNODE,TNODE,ONEWAY")
oneway = [{'F':False,'T':True}[x] for x in dbf.by_col('ONEWAY')]
fnode = dbf.by_col('FNODE')
tnode = dbf.by_col('TNODE')
if distance_metric == EUCLIDEAN_DISTANCE:
lengths = [x.len for x in shp]
elif distance_metric == ARC_DISTANCE:
lengths = [x.arclen for x in shp]
else:
raise ValueError("distance_metric must be either EUCLIDEAN_DISTANCE or ARC_DISTANCE")
self.lengths = lengths
if any(oneway):
G = networkx.MultiDiGraph()
#def isoneway(x):
# return x[-1]
#def isnotoneway(x):
# if(x[-1]):
# return False
# return True
#
#A = filter(isoneway,zip(fnode,tnode,oneway))
#B = filter(isnotoneway,zip(fnode,tnode,oneway))
#C = filter(isnotoneway,zip(tnode,fnode,oneway))
#G.add_edges_from(A)
#G.add_edges_from(B)
#G.add_edges_from(C)
else:
G = networkx.MultiGraph()
#zip(fnode,tnode))
self.G = G
shp.seek(0)
self._locator = Polyline_Shapefile_SegmentLocator(shp)
def snap(self,pt):
i,p,j = self._locator.nearest(pt) #shpID,partID,segmentID
segment = self.shp[i].segments[p][j] #grab segment
d,pct = pysal.cg.get_segment_point_dist(segment,pt) #find pct along segment
x0,x1 = segment.p1[0],segment.p2[0]
x2 = x0 + (x1-x0)*pct # find x location of snap
y2 = segment.line.y(x2) # find y location of snap
#dbf = self.dbf
#rec = dict(zip(dbf.header,dbf[i][0]))
#edge = (rec['FNODE'],rec['TNODE'])
#TODO: Calculate location along edge and distance to edge"
#return edge
return x2,y2
