服务器之家

服务器之家 > 正文

python射线法判断一个点在图形区域内外

时间:2021-07-26 00:04     来源/作者:两鬓已不能斑白

用python 实现的代码:判断一个点在图形区域内外,供大家参考,具体内容如下

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
# -*-encoding:utf-8 -*-
# file:class.py
#
 
"""
信息楼
0 123.425658,41.774177
1 123.425843,41.774166
2 123.425847,41.774119
3 123.42693,41.774062
4 123.426943,41.774099
5 123.427118,41.774089
6 123.427066,41.773548
7 123.426896,41.773544
8 123.426916,41.773920
9 123.425838,41.773965
10 123.425804,41.773585
11 123.425611,41.773595
图书馆
0 123.425649,41.77303
1 123.426656,41.772993
2 123.426611,41.772398
3 123.425605,41.772445
"""
 
 
class Point:
 lat = ''
 lng = ''
 
 def __init__(self,lat,lng):
 self.lat = lat #纬度
 self.lng = lng #经度
 
 def show(self):
 print self.lat," ",self.lng
 
 
#将信息楼的边界点实例化并存储到points1里
point0 = Point(123.425658,41.774177)
point1 = Point(123.425843,41.774166)
point2 = Point(123.425847,41.774119)
point3 = Point(123.42693,41.774062)
point4 = Point(123.426943,41.774099)
point5 = Point(123.427118,41.774089)
point6 = Point(123.427066,41.773548)
point7 = Point(123.426896,41.773544)
point8 = Point(123.426916,41.773920)
point9 = Point(123.425838,41.773961)
point10 = Point(123.425804,41.773585)
point11 = Point(123.425611,41.773595)
 
points1 = [point0,point1,point2,point3,
   point4,point5,point6,point7,
   point8,point9,point10,point11,
  ]
 
 
#将图书馆的边界点实例化并存储到points2里
point0 = Point(123.425649,41.77303)
point1 = Point(123.426656,41.772993)
point2 = Point(123.426611,41.772398)
point3 = Point(123.425605,41.772445)
 
points2 = [point0,point1,point2,point3]
 
 
'''
将points1和points2存储到points里,
points可以作为参数传入
'''
points = [points1,points2]
 
 
'''
输入一个测试点,这个点通过GPS产生
建议输入三个点测试
在信息学馆内的点:123.4263790000,41.7740520000 123.42699,41.773592
在图书馆内的点: 123.4261550000,41.7726740000 123.42571,41.772499 123.425984,41.772919
不在二者内的点: 123.4246270000,41.7738130000
在信息学馆外包矩形内,但不在信息学馆中的点:123.4264060000,41.7737860000
'''
#lat = raw_input(please input lat)
#lng = raw_input(please input lng)
lat = 123.42699
lng = 41.773592
point = Point(lat,lng)
 
debug = raw_input("请输入debug")
if debug == '1':
 debug = True
else:
 debug = False
 
#求外包矩形
def getPolygonBounds(points):
 length = len(points)
 #top down left right 都是point类型
 top = down = left = right = points[0]
 for i in range(1,length):
 if points[i].lng > top.lng:
  top = points[i]
 elif points[i].lng < down.lng:
  down = points[i]
 else:
  pass
 if points[i].lat > right.lat:
  right = points[i]
 elif points[i].lat < left.lat:
  left = points[i]
   else:
   pass
 
 point0 = Point(left.lat,top.lng)
 point1 = Point(right.lat,top.lng)
 point2 = Point(right.lat,down.lng)
 point3 = Point(left.lat,down.lng)
 polygonBounds = [point0,point1,point2,point3]
 return polygonBounds
 
#测试求外包矩形的一段函数
if debug:
 poly1 = getPolygonBounds(points[0])
 print "第一个建筑的外包是:"
 for i in range(0,len(poly1)):
 poly1[i].show()
 poly2 = getPolygonBounds(points[1])
 print "第二个建筑的外包是:"
 for i in range(0,len(poly2)):
 poly2[i].show()
 
 
#判断点是否在外包矩形外
def isPointInRect(point,polygonBounds):
 if point.lng >= polygonBounds[3].lng and \
  point.lng <= polygonBounds[0].lng and \
  point.lat >= polygonBounds[3].lat and \
  point.lat <= polygonBounds[2].lat:\
  return True
 else:
 return False
 
#测试是否在外包矩形外的代码
if debug:
 if(isPointInRect(point,poly1)):
 print "在信息外包矩形内"
 else:
 print "在信息外包矩形外"
 
 if(isPointInRect(point,poly2)):
 print "在图书馆外包矩形内"
 else:
 print "在图书馆外包矩形外"
 
 
 
#采用射线法,计算测试点是否任意一个建筑内
def isPointInPolygon(point,points):
 #定义在边界上或者在顶点都建筑内
 Bound = Vertex = True
 count = 0
 precision = 2e-10
 
 #首先求外包矩形
 polygonBounds = getPolygonBounds(points)
 
 #然后判断是否在外包矩形内,如果不在,直接返回false
 if not isPointInRect(point, polygonBounds):
 if debug:
  print "在外包矩形外"
 return False
 else:
 if debug:
  print "在外包矩形内"
 
 length = len(points)
 p = point
 p1 = points[0]
 for i in range(1,length):
 if p.lng == p1.lng and p.lat == p1.lat:
  if debug:
  print "Vertex1"
  return Vertex
 
 p2 = points[i % length]
 if p.lng == p2.lng and p.lat == p2.lat:
  if dubug:
  print "Vertex2"
  return Vertex
 
 if debug:
  print i-1,i
  print "p:"
  p.show()
  print "p1:"
  p1.show()
  print "p2:"
  p2.show()
 
 if p.lng < min(p1.lng,p2.lng) or \
  p.lng > max(p1.lng,p2.lng) or \
  p.lat > max(p1.lat,p2.lat):
  p1 = p2
  if debug:
  print "Outside"
  continue
 
 elif p.lng > min(p1.lng,p2.lng) and \
  p.lng < max(p1.lng,p2.lng):
  if p1.lat == p2.lat:
  if p.lat == p1.lat and \
   p.lng > min(p1.lng,p2.lng) and \
   p.lng < max(p1.lng,p2.lng):
   return Bound
  else:
   count = count + 1
   if debug:
   print "count1:",count
   continue
  if debug:
  print "into left or right"  
 
  a = p2.lng - p1.lng
  b = p1.lat - p2.lat
  c = p2.lat * p1.lng - p1.lat * p2.lng
  d = a * p.lat + b * p.lng + c
  if p1.lng < p2.lng and p1.lat > p2.lat or \
   p1.lng < p2.lng and p1.lat < p2.lat:
  if d < 0:
   count = count + 1
   if debug:
   print "count2:",count
  elif d > 0:
   p1 = p2
   continue
  elif abs(p.lng-d) < precision :
   return Bound
  else :   
  if d < 0:
   p1 = p2
   continue
  elif d > 0:
   count = count + 1
   if debug:
   print "count3:",count
  elif abs(p.lng-d) < precision :
   return Bound
 else:
  if p1.lng == p2.lng:
  if p.lng == p1.lng and \
   p.lat > min(p1.lat,p2.lat) and \
   p.lat < max(p1.lat,p2.lat):
    return Bound
  else:
  p3 = points[(i+1) % length]
  if p.lng < min(p1.lng,p3.lng) or \
   p.lng > max(p1.lng,p3.lng):
   count = count + 2
   if debug:
   print "count4:",count
  else:
   count = count + 1
   if debug:
   print "count5:",count
 p1 = p2
 if count % 2 == 0 :
 return False
 else :
 return True
 
 
 
length = len(points)
flag = 0
for i in range(length):
 if isPointInPolygon(point,points[i]):
 print "你刚才输入的点在第 %d 个建筑里" % (i+1)
 print "然后根据i值,可以读出建筑名,或者修改传入的points参数"
 break
 else:
 flag = flag + 1
 
if flag == length:
 print "在头 %d 建筑外" % (i+1)

 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/u010429424/article/details/44830379

标签:

相关文章

热门资讯

2020微信伤感网名听哭了 让对方看到心疼的伤感网名大全
2020微信伤感网名听哭了 让对方看到心疼的伤感网名大全 2019-12-26
yue是什么意思 网络流行语yue了是什么梗
yue是什么意思 网络流行语yue了是什么梗 2020-10-11
背刺什么意思 网络词语背刺是什么梗
背刺什么意思 网络词语背刺是什么梗 2020-05-22
苹果12mini价格表官网报价 iPhone12mini全版本价格汇总
苹果12mini价格表官网报价 iPhone12mini全版本价格汇总 2020-11-13
2021德云社封箱演出完整版 2021年德云社封箱演出在线看
2021德云社封箱演出完整版 2021年德云社封箱演出在线看 2021-03-15
返回顶部