多边形节点编码python脚本

# -*- coding: cp936 -*-
#本脚以最左边、Y值最大的点为起始点按顺时针为多边形节点编码,生成一个包含记录编码值和多边形FID字段的点要素类

#注意：
#1.本脚本作为arcgis脚本工具使用、脚本测试版本为10.0中文，未装sp5补丁
#2.暂不支持带环多边形，处理带环多边形程序直接崩溃
#3.本工具脚本用到系统工具"多部分(Multipart)至单部分(Singlepart)",因该工具无法完美处理所有的CAD多边形要素类,
#  所以本脚本工具只支持简单CAD多边形要素类。

#Creater: ych
#Create Time:2013年5月1日

import arcpy
import os

#获取单部分多边形最右边且Y值最大的点(边线相交的多边形不适合)
def getRightupperPoint(fc): 
    points = [point for point in fc.getPart(0)]
    XValues = [point.X for point in points]
    Xmax_indexs = [XValues.index(x) for x in XValues if x == max(XValues)]
    Ymax_index = [i for i in Xmax_indexs if points[i].Y == max([points[j].Y for j in Xmax_indexs ])][0]
    RightupperPoint = points[Ymax_index]
    return   RightupperPoint,Ymax_index

#判断单部分多边形的方向(True 为顺时针，False为逆时针 圆、椭圆返回-1)     
def isclockwise(fc): 
     #找出最右且Y值最大的节点
     points = [point for point in fc.getPart(0)]
     if len(points)!= 2:
        rightupperPoint,rightupperPoint_index = getRightupperPoint(fc)
    
        #如果最右且Y值最大的节点的后一个点(以在points列表中的顺序为参考顺序 )的Y值,比最右且Y值
        #最大的节点的前一个点的Y值大，则多边形为顺时针，否则为逆时针     
        if rightupperPoint_index == len(points)-1:
           BehindPt = points[1]
        else:
           BehindPt = points[rightupperPoint_index+1]
       
        prePt = points[rightupperPoint_index-1]
    
        if prePt.X == rightupperPoint.X:
            return True
        else:
            y = (prePt.Y - rightupperPoint.Y)*(BehindPt.X - rightupperPoint.X)/(prePt.X - rightupperPoint.X ) + rightupperPoint.Y

        if y <BehindPt.Y:
             return True
        else:
             return False
     else:
        return -1
         
           
       
#将单部分多边形要素的起始点只设置为最右且Y值最大的点
def changeStartPoint(fc):
      points = [point for point in fc.getPart(0)]
      if len(points)!= 2:
         #计算多边形最右边且Y值最大的点在Points中索引
         index_RightupperPoint = getRightupperPoint(fc)[1]
         #计算更改了起始点的多边形要素的newpoints
         newpoints =[]
         newpoints.extend(points[index_RightupperPoint:-1])
         newpoints.extend(points[:index_RightupperPoint+1])
         #创建新要素
         newPolygon = arcpy.Polygon(arcpy.Array(newpoints))
         return newPolygon
      #len(points) ==2为圆、椭圆 
      else:
         return fc
    
     

   
#主程序
def main():
  #设置参数
  fcl_input = arcpy.GetParameterAsText(0)  #输入多边形要素类
  out_PointClass = arcpy.GetParameterAsText(1) #输出点要素类

  #创建空的、包含用于存储节点编号的子段的点要素类
  name = os.path.basename(out_PointClass)
  path = out_PointClass[:-(len(name)+1)]
  desc = arcpy.Describe(fcl_input)
  pointClass = arcpy.CreateFeatureclass_management(path,name,"POINT","","","",desc.spatialReference)
 
  #添加字段
  arcpy.AddField_management(pointClass,"NodeCode","SHORT")
  arcpy.AddField_management(pointClass,"PolygonFID","LONG")

  #多部分至单部分
  scrathName = arcpy.CreateScratchName ("TEMP","","",path)
  fcl_input=arcpy.MultipartToSinglepart_management (fcl_input,scrathName)

  #创建cursor
  rows = arcpy.InsertCursor(pointClass)
  rows_fc = arcpy.SearchCursor(fcl_input)
 
 
  #输入多边形要素类的FID字段
  fcID = arcpy.ListFields(fcl_input,"","OID")
 

  for row_fc in rows_fc:
        fc = row_fc.shape
        #将多边形要素的起始点只设置为最右且Y值最大的点
        fc = changeStartPoint(fc)
        #获取多边形节点列表
        points = [point for point in fc.getPart(0)]
        #如果多边形为逆时针，则翻转节点列表，使多边形变成顺时针方向
        if isclockwise(fc)==False: 
           points.reverse()   
        else:
           pass
        #将顺时针方向的多边形点列表写到多边形要素类中
        for point in  points[:-1]:    
           newrow = rows.newRow()
           newrow.shape = point
           newrow.NodeCode =points.index(point)+1
           newrow.PolygonFID = eval("row_fc."+fcID[0].name)
           rows.insertRow(newrow)
        arcpy.AddMessage("Nodes of Polygon %s has been successfully decoded."% eval("row_fc."+fcID[0].name))    
  #删除游标
  del rows,rows_fc,row_fc
  #删除临时文件
  arcpy.Delete_management (fcl_input)

if __name__ == "__main__":

    main()

来自：http://bbs.esrichina-bj.cn/esri/viewthread.php?tid=127216