Python編程使用matplotlib繪制動態(tài)圓錐曲線示例
作為讓高中生心臟驟停的四個字,對于高考之后的人來說可謂刻骨銘心,所以定義不再贅述,直接擼圖,其標準方程分別為

在Python中,繪制動圖需要用到matplotlib中的animation包,其調(diào)用方法以及接下來要用到的參數(shù)為
ani = animation.FuncAnimation(fig, func, frames, interval)
其中fig為繪圖窗口,func為繪圖函數(shù),其返回值為圖像,frames為迭代參數(shù),如果為整型的話,其迭代參數(shù)則為range(frames)。
橢圓
為了繪圖方便,橢圓的參數(shù)方程為


代碼為:
# 這三個包在后面的程序中不再復(fù)述
import numpy as np
import matplotlib.pyplot as plt
import matplotlib.animation as animation
a,b,c = 5,3,4
fig = plt.figure(figsize=(12,9))
ax = fig.add_subplot(autoscale_on=False,
xlim=(-a,a),ylim=(-b,b))
ax.grid()
line, = ax.plot([],[],'o-',lw=2)
trace, = ax.plot([],[],'-', lw=1)
theta_text = ax.text(0.02,0.85,'',transform=ax.transAxes)
textTemplate = '''theta = %.1f°\n
lenL = %.1f, lenR = %.1f\n
lenL+lenR = %.1f'''
xs,ys = [], []
def animate(i):
if(i==0):
xs.clear()
ys.clear()
theta = i*0.04
x = a*np.cos(theta)
y = b*np.sin(theta)
xs.append(x)
ys.append(y)
line.set_data([-c,x,c], [0,y,0])
trace.set_data(xs,ys)
lenL = np.sqrt((x+c)**2+y**2)
lenR = np.sqrt((x-c)**2+y**2)
theta_text.set_text(textTemplate %
(180*theta/np.pi, lenL, lenR, lenL+lenR))
return line, trace, theta_text
ani = animation.FuncAnimation(fig, animate, 157,
interval=5, blit=True)
ani.save("ellipse.gif")
plt.show()
雙曲線
雙曲線的參數(shù)方程為

設(shè) a = 4 , b = 3 , c = 5 則代碼如下
a,b,c = 4,3,5
fig = plt.figure(figsize=(12,9))
ax = fig.add_subplot(autoscale_on=False,
xlim=(-c,16),ylim=(-12,12))
ax.grid()
line, = ax.plot([],[],'o-',lw=2)
trace, = ax.plot([],[],'-', lw=1)
theta_text = ax.text(0.01,0.85,'',
transform=ax.transAxes)
textTemplate = '''t = %.1f\n
lenL = %.1f, lenR = %.1f\n
lenL-lenR = %.1f'''
xs,ys = [],[]
def animate(t):
if(t==-3):
xs.clear()
ys.clear()
x = a*np.cosh(t)
y = b*np.sinh(t)
xs.append(x)
ys.append(y)
line.set_data([-c,x,c], [0,y,0])
trace.set_data(xs,ys)
lenL = np.sqrt((x+c)**2+y**2)
lenR = np.sqrt((x-c)**2+y**2)
theta_text.set_text(textTemplate %
(t, lenL, lenL, lenL-lenR))
return line, trace, theta_text
frames = np.arange(-3,3,0.05)
ani = animation.FuncAnimation(fig, animate,
frames, interval=5, blit=True)
ani.save("hyperbola.gif")
plt.show()

拋物線

import numpy as np
import matplotlib.pyplot as plt
import matplotlib.animation as animation
a,b,c = 4,3,5
p = 1
fig = plt.figure(figsize=(12,9))
ax = fig.add_subplot(autoscale_on=False,
xlim=(-0.6,4.5),ylim=(-3,3))
ax.grid()
ax.plot([-p/2,-p/2],[-5,5],'-',lw=2)
line, = ax.plot([],[],'o-',lw=2)
trace, = ax.plot([],[],'-', lw=1)
theta_text = ax.text(0.05,0.85,'',
transform=ax.transAxes)
textTemplate = '''y = %.1f\n
lenL = %.1f, lenF = %.1f\n
lenL-lenF = %.1f'''
xs,ys = [],[]
def animate(y):
if(y==-3):
xs.clear()
ys.clear()
x = y**2/p/2
xs.append(x)
ys.append(y)
line.set_data([-p,x,p/2], [y,y,0])
trace.set_data(xs,ys)
lenL = x+p/2
lenF = np.sqrt((x-p/2)**2+y**2)
theta_text.set_text(textTemplate %
(y, lenL, lenF, lenL-lenF))
return line, trace, theta_text
frames = np.arange(-3,3,0.1)
ani = animation.FuncAnimation(fig, animate,
frames, interval=5, blit=True)
ani.save("parabola.gif")
plt.show()

極坐標方程
圓錐曲線在極坐標系下有相同的表達式,即

在matplotlib中,極坐標圖像需要通過projection='polar'來標識,其代碼為
p = 2
fig = plt.figure(figsize=(12,9))
ax = fig.add_subplot(autoscale_on=False, projection='polar')
ax.set_rlim(0,8)
trace, = ax.plot([],[],'-', lw=1)
theta_text = ax.text(0.05,0.95,'',transform=ax.transAxes)
textTemplate = 'e = %.1f\n'
theta = np.arange(-3.1,3.2,0.1)
def animate(e):
rho = p/(1-e*np.cos(theta))
trace.set_data(theta,rho)
theta_text.set_text(textTemplate % e)
return trace, theta_text
frames = np.arange(-2,2,0.1)
ani = animation.FuncAnimation(fig, animate,
frames, interval=100, blit=True)
ani.save("polar.gif")
plt.show()

以上就是Python使用matplotlib繪制動態(tài)的圓錐曲線示例的詳細內(nèi)容,更多關(guān)于matplotlib繪制動態(tài)圓錐曲線的資料請關(guān)注本站其它相關(guān)文章!
版權(quán)聲明:本站文章來源標注為YINGSOO的內(nèi)容版權(quán)均為本站所有,歡迎引用、轉(zhuǎn)載,請保持原文完整并注明來源及原文鏈接。禁止復(fù)制或仿造本網(wǎng)站,禁止在非maisonbaluchon.cn所屬的服務(wù)器上建立鏡像,否則將依法追究法律責任。本站部分內(nèi)容來源于網(wǎng)友推薦、互聯(lián)網(wǎng)收集整理而來,僅供學習參考,不代表本站立場,如有內(nèi)容涉嫌侵權(quán),請聯(lián)系alex-e#qq.com處理。
關(guān)注官方微信