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
- #!/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]]))
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w3xue。