伙计我以前曾问过这个问题，但没有收到任何评论或回答
我想在幂律图上模拟搜索算法，并希望直观地看到算法在图上从一个节点移动到另一个节点。我该怎么做？
答案 0 :(得分：2)
您可以调整我恰好为Find the most points enclosed in a fixed size circle编写的完全不同的代码：）
有用的一点是：
它使用基本窗口系统 tkinter 来创建包含画布的框架;它然后执行一些算法，调用它自己的“draw()”来更改画布，然后“update()”重新绘制屏幕，延迟。从查看tkinter中的图表是多么容易，您可以继续使用交互式版本等。
import random, math, time
from Tkinter import * # our UI
def sqr(x):
return x*x
class Point:
def __init__(self,x,y):
self.x = float(x)
self.y = float(y)
self.left = 0
self.right = []
def __repr__(self):
return "("+str(self.x)+","+str(self.y)+")"
def distance(self,other):
return math.sqrt(sqr(self.x-other.x)+sqr(self.y-other.y))
def equidist(left,right,dist):
u = (right.x-left.x)
v = (right.y-left.y)
if 0 != u:
r = math.sqrt(sqr(dist)-((sqr(u)+sqr(v))/4.))
theta = math.atan(v/u)
x = left.x+(u/2)-(r*math.sin(theta))
if x < left.x:
x = left.x+(u/2)+(r*math.sin(theta))
y = left.y+(v/2)-(r*math.cos(theta))
else:
y = left.y+(v/2)+(r*math.cos(theta))
else:
theta = math.asin(v/(2*dist))
x = left.x-(dist*math.cos(theta))
y = left.y + (v/2)
return Point(x,y)
class Vis:
def __init__(self):
self.frame = Frame(root)
self.canvas = Canvas(self.frame,bg="white",width=width,height=height)
self.canvas.pack()
self.frame.pack()
self.run()
def run(self):
self.count_calc0 = 0
self.count_calc1 = 0
self.count_calc2 = 0
self.count_calc3 = 0
self.count_calc4 = 0
self.count_calc5 = 0
self.prev_x = 0
self.best = -1
self.best_centre = []
for self.sweep in xrange(0,len(points)):
self.count_calc0 += 1
if len(points[self.sweep].right) <= self.best:
break
self.calc(points[self.sweep])
self.sweep = len(points) # so that draw() stops highlighting it
print "BEST",self.best+1, self.best_centre # count left-most point too
print "counts",self.count_calc0, self.count_calc1,self.count_calc2,self.count_calc3,self.count_calc4,self.count_calc5
self.draw()
def calc(self,p):
for self.right in p.right:
self.count_calc1 += 1
if (self.right.left + len(self.right.right)) < self.best:
# this can never help us
continue
self.count_calc2 += 1
self.centre = equidist(p,self.right,radius)
assert abs(self.centre.distance(p)-self.centre.distance(self.right)) < 1
count = 0
for p2 in p.right:
self.count_calc3 += 1
if self.centre.distance(p2) <= radius:
count += 1
if self.best < count:
self.count_calc4 += 4
self.best = count
self.best_centre = [self.centre]
elif self.best == count:
self.count_calc5 += 5
self.best_centre.append(self.centre)
self.draw()
self.frame.update()
time.sleep(0.1)
def draw(self):
self.canvas.delete(ALL)
# draw best circle
for best in self.best_centre:
self.canvas.create_oval(best.x-radius,best.y-radius,\
best.x+radius+1,best.y+radius+1,fill="red",\
outline="red")
# draw current circle
if self.sweep < len(points):
self.canvas.create_oval(self.centre.x-radius,self.centre.y-radius,\
self.centre.x+radius+1,self.centre.y+radius+1,fill="pink",\
outline="pink")
# draw all the connections
for p in points:
for p2 in p.right:
self.canvas.create_line(p.x,p.y,p2.x,p2.y,fill="lightGray")
# plot visited points
for i in xrange(0,self.sweep):
p = points[i]
self.canvas.create_line(p.x-2,p.y,p.x+3,p.y,fill="blue")
self.canvas.create_line(p.x,p.y-2,p.x,p.y+3,fill="blue")
# plot current point
if self.sweep < len(points):
p = points[self.sweep]
self.canvas.create_line(p.x-2,p.y,p.x+3,p.y,fill="red")
self.canvas.create_line(p.x,p.y-2,p.x,p.y+3,fill="red")
self.canvas.create_line(p.x,p.y,self.right.x,self.right.y,fill="red")
self.canvas.create_line(p.x,p.y,self.centre.x,self.centre.y,fill="cyan")
self.canvas.create_line(self.right.x,self.right.y,self.centre.x,self.centre.y,fill="cyan")
# plot unvisited points
for i in xrange(self.sweep+1,len(points)):
p = points[i]
self.canvas.create_line(p.x-2,p.y,p.x+3,p.y,fill="green")
self.canvas.create_line(p.x,p.y-2,p.x,p.y+3,fill="green")
radius = 60
diameter = radius*2
width = 800
height = 600
points = []
# make some points
for i in xrange(0,100):
points.append(Point(random.randrange(width),random.randrange(height)))
# sort points for find-the-right sweep
points.sort(lambda a, b: int(a.x)-int(b.x))
# work out those points to the right of each point
for i in xrange(0,len(points)):
p = points[i]
for j in xrange(i+1,len(points)):
p2 = points[j]
if p2.x > (p.x+diameter):
break
if (abs(p.y-p2.y) <= diameter) and \
p.distance(p2) < diameter:
p.right.append(p2)
p2.left += 1
# sort points in potential order for sweep, point with most right first
points.sort(lambda a, b: len(b.right)-len(a.right))
# debug
for p in points:
print p, p.left, p.right
# show it
root = Tk()
vis = Vis()
root.mainloop()
答案 1 :(得分：2)
您可以使用matplotlib。
以下是带有动画突出显示点的网格的简单示例：
import matplotlib.pyplot as plt
import time
x_size = 4
y_size = 3
# create the points and edges of the mesh
points = [(x,y) for y in range(y_size) for x in range(x_size)]
vert_edges = [((i_y*x_size)+i_x,(i_y*x_size)+i_x+1)
for i_x in range(x_size-1) for i_y in range(y_size)]
horz_edges = [((i_y*x_size)+i_x,((i_y+1)*x_size)+i_x)
for i_x in range(x_size) for i_y in range(y_size-1)]
edges = vert_edges + horz_edges
# plot all the points and edges
lines = []
for edge in edges:
x_coords, y_coords = zip(points[edge[0]], points[edge[1]])
lines.extend((x_coords, y_coords, 'g'))
plt.plot(linewidth=1, *lines)
x, y = zip(*points)
plt.plot(x, y, 'o')
# create the highlighted point
point_plot = plt.plot([0], [0], 'ro')[0]
# turn on interactive plotting mode
plt.ion()
plt.ylim(-1, y_size)
plt.xlim(-1, x_size)
# animate the highlighted point
for i_point in range(1, len(x)):
point_plot.set_xdata([x[i_point]])
point_plot.set_ydata([y[i_point]])
plt.draw()
time.sleep(0.5)
plt.show()