简单实现python画圆功能

本文实例为大家分享了python实现画圆功能的具体代码，供大家参考，具体内容如下

import numpy as np
import matplotlib.pyplot as plt
from matplotlib.patches import Polygon
import matplotlib.patches as mpatches

fig = plt.figure(figsize = (16,8))
ax = fig.gca()
ax.set_xlim(-5,18)
ax.set_ylim(-5,8)
alpha = np.linspace(-np.pi,np.pi,30)  
t = np.linspace(-np.pi,np.pi,100)
def ppp(nc , na , c , sx , sy):
beta = alpha[na]
gam = alpha[na+1]
x = [] ; y = [] ;
r = 0.5*nc
x.append(r*np.cos(beta)) ; y.append(r*np.sin(beta)) ;
tt = np.linspace(beta,gam,10)
for i in range(len(tt)):
 x.append(r*np.cos(tt[i]))
 y.append(r*np.sin(tt[i]))
r-=0.5
x.append(r*np.cos(gam)) ; y.append(r*np.sin(gam))
tt = np.linspace(gam,beta,10)
for i in range(len(tt)):
 x.append(r*np.cos(tt[i])) ; y.append(r*np.sin(tt[i]))
x = np.array(x) ; y = np.array(y)
verts = list(zip(x+sx,y+sy))
poly = Polygon(verts , facecolor=c , edgecolor=c)
ax.add_patch(poly)

#ppp(2,0,'r',0,0)
def get_coordiate(x , y):
beta = (alpha[y]+alpha[y+1])/2
pr = 0.5*(x+x-1)/2
sx = pr*np.cos(beta) ; sy = pr*np.sin(beta)
return sx,sy
def pp_arrow(x,y):
print x , y
sx , sy = get_coordiate(x, y)
for i in range(-1,2):
 for j in range(-1,2):
  if i == 0 and j == 0:
   continue
  ex , ey = get_coordiate(x+i, y+j)
  ax.arrow(sx,sy,ex-sx,ey-sy,head_width=0.05,head_length=0.1,fc='r',ec='r')

def pxy(cx,cy):
for i in range(10):
 plt.plot(0.5*i*np.cos(t)+cx,0.5*i*np.sin(t)+cy)  
for i in range(len(alpha)):
 plt.plot((0.5*np.cos(alpha)+cx,4.5*np.cos(alpha)+cx),(0.5*np.sin(alpha)+cy,4.5*np.sin(alpha)+cy))

cx = 13 ; cy =0
pxy(0,0)
pxy(13,0)

mr = np.zeros((10,30))
mb = np.zeros((10,30))

for i in range(3,9):
for j in range(1,27):
 ttt = np.random.random()
 if ttt >= 0.98 and ttt <= 1:
  ppp(i,j,'r',0,0)
  mr[i][j] = 1
  continue
 if ttt < 0.8:
  continue
 else:
  ppp(i,j,'b',0,0)
  mb[i][j] = 1

for i in range(10):
for j in range(30):
 if mr[i][j] == 0:
  continue
 pp_arrow(i, j)
 ma = 0 ;posx = 1 ; posy = 1
 for k in range(-1,2):
  for s in range(-1,2):
   mb[i+k][j+s]=0
   ttt = np.random.random()
   if ttt > ma:
    ma = ttt
    posx = k ; posy = s
 ppp(i+posx , j+posy , 'r' , 13 , 0)
 ppp(i,j,'g',13,0)

for i in range(10):
for j in range(30):
 if mb[i][j] == 0:
  continue
 ppp(i , j , 'b' , 13 , 0)

arrow = mpatches.Arrow(5, 0
     ,3,0,width = 1,color = 'r')
ax.add_patch(arrow)
ax.text(6.2,0.5,'after one\nunit time',ha='center',va='center',color='y')

xx = [4,4,4]
yy = [7.5,6.5,5.5]
c = ['b' , 'r' , 'g']
s = ['debris','satellite' , 'the location of satellite one unit time ago']
for i in range(3):
print xx[i] , yy[i]
rect = mpatches.Rectangle((xx[i],yy[i]),0.5,0.3,ec = c[i],fc=c[i] )
ax.text(xx[i]+0.7,yy[i],s[i])
ax.add_patch(rect)
plt.axis('off')
plt.show()

来源：http://blog.csdn.net/cq_pf/article/details/50629768