本文实例为大家分享了python3射线法判断点是否在多边形内的具体代码,供大家参考,具体内容如下
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#!/usr/bin/python3.4
# -*- coding:utf-8 -*-
def isPointinPolygon(point, rangelist): #[[0,0],[1,1],[0,1],[0,0]] [1,0.8]
# 判断是否在外包矩形内,如果不在,直接返回false
lnglist = []
latlist = []
for i in range ( len (rangelist) - 1 ):
lnglist.append(rangelist[i][ 0 ])
latlist.append(rangelist[i][ 1 ])
print (lnglist, latlist)
maxlng = max (lnglist)
minlng = min (lnglist)
maxlat = max (latlist)
minlat = min (latlist)
print (maxlng, minlng, maxlat, minlat)
if (point[ 0 ] > maxlng or point[ 0 ] < minlng or
point[ 1 ] > maxlat or point[ 1 ] < minlat):
return False
count = 0
point1 = rangelist[ 0 ]
for i in range ( 1 , len (rangelist)):
point2 = rangelist[i]
# 点与多边形顶点重合
if (point[ 0 ] = = point1[ 0 ] and point[ 1 ] = = point1[ 1 ]) or (point[ 0 ] = = point2[ 0 ] and point[ 1 ] = = point2[ 1 ]):
print ( "在顶点上" )
return False
# 判断线段两端点是否在射线两侧 不在肯定不相交 射线(-∞,lat)(lng,lat)
if (point1[ 1 ] < point[ 1 ] and point2[ 1 ] > = point[ 1 ]) or (point1[ 1 ] > = point[ 1 ] and point2[ 1 ] < point[ 1 ]):
# 求线段与射线交点 再和lat比较
point12lng = point2[ 0 ] - (point2[ 1 ] - point[ 1 ]) * (point2[ 0 ] - point1[ 0 ]) / (point2[ 1 ] - point1[ 1 ])
print (point12lng)
# 点在多边形边上
if (point12lng = = point[ 0 ]):
print ( "点在多边形边上" )
return False
if (point12lng < point[ 0 ]):
count + = 1
point1 = point2
print (count)
if count % 2 = = 0 :
return False
else :
return True
if __name__ = = '__main__' :
print (isPointinPolygon([ 0.8 , 0.8 ], [[ 0 , 0 ],[ 1 , 1 ],[ 0 , 1 ],[ 0 , 0 ]]))
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以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持服务器之家。
原文链接:https://blog.csdn.net/sinat_36811967/article/details/78607007