怎么用python画圆的公式_运用python 画圆[通俗易懂]

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()