多边形节点编码python脚本

提示：扫一扫查出行
【扫一扫了解最新限行尾号】
复制提示

# -*- 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)