visualizations

Programmatic visualizations
git clone git://git.laack.co/visualizations.git
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prim.py (1644B)

      1 import heapq
      2 import random
      3 import math
      4 
      5 VERTICES = 100000
      6 EDGES = 1000000
      7 
      8 white = (255, 255, 255)
      9 red = (255, 0, 0)
     10 black = (0, 0, 0)
     11 grey = (100,100,100)
     12 light_grey = (50,50,50)
     13 
     14 
     15 class Vertex():
     16     def __init__(self, x, y):
     17         self.x = x
     18         self.y = y
     19         self.visited = False
     20 
     21 class Edge():
     22     def __init__(self, v1, v2):
     23         self.v1 = v1
     24         self.v2 = v2
     25         self.dist = math.sqrt(((v1.x - v2.x) ** 2) + ((v1.y - v2.y) ** 2))
     26 
     27     def __lt__(self,otr):
     28         return self.dist < otr.dist
     29 
     30 
     31 graph = {}
     32 
     33 for i in range(0,VERTICES):
     34     x = random.random() * 5120
     35     y = random.random() * 1440
     36     graph[Vertex(x,y)] = []
     37 
     38 
     39 edge_list = []
     40 keys = list(graph.keys())
     41 
     42 for i in range(0,EDGES):
     43     k1 = None
     44     k2 = None
     45     while k1 == k2:
     46         k1 = random.choice(keys)
     47         k2 = random.choice(keys)
     48 
     49     edge = Edge(k1,k2)
     50     graph[k1].append(edge)
     51     graph[k2].append(edge)
     52     edge_list.append(edge)
     53 
     54 
     55 edge_heap = []
     56 visited_vertices = set()
     57 
     58 mst = []
     59 
     60 start = random.choice(list(graph.keys()))
     61 start.visited = True
     62 visited_vertices.add(start)
     63 for edge in graph[start]:
     64     heapq.heappush(edge_heap, edge)
     65 
     66 while True:
     67     item = None
     68     while edge_heap:
     69         candidate = heapq.heappop(edge_heap)
     70         if (candidate.v1 in visited_vertices) != (candidate.v2 in visited_vertices):
     71             item = candidate
     72             break
     73 
     74     if item is None:
     75         break
     76 
     77     new_vertex = item.v2 if item.v1 in visited_vertices else item.v1
     78     visited_vertices.add(new_vertex)
     79     new_vertex.visited = True
     80     mst.append(item)
     81     for edge in graph[new_vertex]:
     82         heapq.heappush(edge_heap, edge)