내가 사용하는 알고리즘.
- 유클리드 최소 스패닝 포인트 트리를 계산합니다.
- 이 네트워크에서 서로 가장 멀리있는 2 개의 포인트를 찾습니다.
- 그들 사이에서 가장 짧은 경로를 찾으십시오.
보시다시피 날카로운 회전으로 코너를자를 수 있습니다.
위 알고리즘의 ArcGIS python 구현이 있으며 networkx 모듈을 사용합니다. 이것이 관심 있는지 알려 주시면 스크립트로 답변을 업데이트하겠습니다.
최신 정보:
# Connects points to make polyline. Makes 1 line at a time
# Tool assumes that 1st layer in Table of Conternt is TARGET polyline feature class,
# second layer in TOC is SOURCE point fc.
# If no selection found in SOURCE layer, works on entire dataset
import arcpy, traceback, os, sys
import itertools as itt
from math import sqrt
sys.path.append(r'C:\Users\felix_pertziger\AppData\Roaming\Python\Python27\site-packages')
import networkx as nx
from networkx import dijkstra_path_length
try:
def showPyMessage():
arcpy.AddMessage(str(time.ctime()) + " - " + message)
def CheckLayerLine(infc):
d=arcpy.Describe(infc)
theType=d.shapeType
if theType!="Polyline":
arcpy.AddWarning("\nTool designed to work with polylines as TARGET!")
raise NameError, "Wrong input\n"
return d
def CheckLayerPoint(infc):
d=arcpy.Describe(infc)
theType=d.shapeType
if theType!="Point":
arcpy.AddWarning("\nTool designed to work with points as SOURCE!")
raise NameError, "Wrong input\n"
return d
mxd = arcpy.mapping.MapDocument("CURRENT")
layers = arcpy.mapping.ListLayers(mxd)
if len(layers)<=1:
arcpy.AddWarning("\nNot enough layers in the view!")
raise NameError, "Wrong input\n"
destLR, sourceLR=layers[0],layers[1]
a = CheckLayerPoint(sourceLR);d = CheckLayerLine(destLR)
# copy all points to manageable list
g=arcpy.Geometry()
geometryList=arcpy.CopyFeatures_management(sourceLR,g)
nPoints=len(geometryList)
arcpy.AddMessage('Computing minimum spanning tree')
list2connect=[p.firstPoint for p in geometryList]
# create network
p=list(itt.combinations(range(nPoints), 2))
arcpy.SetProgressor("step", "", 0, len(p),1)
G=nx.Graph()
for f,t in p:
p1=list2connect[f]
p2=list2connect[t]
dX=p2.X-p1.X;dY=p2.Y-p1.Y
lenV=sqrt(dX*dX+dY*dY)
G.add_edge(f,t,weight=lenV)
arcpy.SetProgressorPosition()
arcpy.AddMessage(len(G.edges()))
mst=nx.minimum_spanning_tree(G)
del G
# find remotest pair
arcpy.AddMessage(len(mst.edges()))
length0=nx.all_pairs_dijkstra_path_length(mst)
lMax=0
for f,t in p:
lCur=length0[f][t]
if lCur>lMax:
lMax=lCur
best=(f,t)
gL=nx.dijkstra_path(mst,best[0],best[1])
del mst
nPoints=len(gL)
ordArray=arcpy.Array()
for i in gL: ordArray.add(list2connect[i])
# append line to TARGET
curT = arcpy.da.InsertCursor(destLR,"SHAPE@")
curT.insertRow((arcpy.Polyline(ordArray),))
arcpy.RefreshActiveView()
del curT
except:
message = "\n*** PYTHON ERRORS *** "; showPyMessage()
message = "Python Traceback Info: " + traceback.format_tb(sys.exc_info()[2])[0]; showPyMessage()
message = "Python Error Info: " + str(sys.exc_type)+ ": " + str(sys.exc_value) + "\n"; showPyMessage()
