如何将这个情节变成动画？我有一个情节，但想以某种方式将其变成动画

Question

在最近的几个晚上，我一直在努力如何在每个时间步长或每个x步长后将此处的波形转换为某种动画。我该如何修改和编写代码，以便使程序的每一步动画都以某种方式出现。我对python和编程非常陌生，以前从未使用过matplotlib的动画部分。

import numpy as np
import matplotlib
import matplotlib.pyplot as plt
import matplotlib.animation as animation




T = 20.0 # t
X = 10.0 # x

n = 300
m = 300

#positions of time and space, xp= x position accross grid, tp = t position accross grid
tp = T / (n - 1)
xp = X / (m - 1)

C = 0.5

U = np.zeros((n, m))

# Set the initial values for each x position
for i in range(0, n):
    U[i, 0] = np.exp(- (i * xp - 2.5) ** 2)


for i in range(1, n): # across x
    for j in range(1, m): # across t
        U[i, j] = (xp * U[i, j - 1] + C * tp * U[i - 1, j]) / (xp + C * tp) # equation for new distribution value

fig = plt.figure(1)

#gives time position instead of time step
tn = np.zeros((m, 1))
for j in range(0, m):
    tn[j] = j * tp

#gives x position instead of x step
xn = np.zeros((n, 1))
for j in range(0, n):
    xn[j] = j * xp

for i in [0, 50, 100, 150, 200, 250, 299 ]: # selects which position of time 
    label = 't = ' + str(tn[i][0]) # lables legend
    subfig = fig.add_subplot(1, 1, 1)
    subfig.plot(xn, U[:, i], label=label)
    subfig.legend()
    subfig.grid(True)
    print(tn)

# Save Image
plt.xlabel('x: position')
plt.ylabel('u: u(x, t)')
plt.title(r'$\frac{\partial u}{\partial t} + C \frac{\partial u}{\partial x} = 0$')

plt.savefig('transport-equation')`

Answer 1

plt是一个很难适应的软件包。通常，图形不是一件容易的事，并且要尽量简化，同时还要提供最大的灵活性。通常，使用plt时，会为您自动生成，更新，清除和处理许多全局变量。使用“ plt.xlabel”时，实际上是将其应用于特定图中的特定轴，这些轴将自动为您确定。如果要在plt中进行更多控制和/或要执行复杂的操作（例如动画），则需要使全局变量明确。

#Create xn and U. 

import matplotlib.pyplot as plt

figure = plt.figure()                     #This is the window that pops open. 
axis   = figure.add_subplot(1,1,1)        #This is a graph/grid.  
axis.grid(True)                           #Add a grid to the axis. 
label  = 't = ' + str(tn[i][0])
plots  = axis.plot(xn,U[:,0],label=label) #These are the plots of data with X and Y. 

X和Y数组一次可以生成多个图，因此，图是其中包含一项的列表。为了了解它是如何工作的，您可以实时地实际操作数据并在plt窗口中查看数据的变化。

figure.show()
plots[0].set_ydata(U[:,10])
plots[0].set_ydata(U[:,-1])
# Close the window when done. 

要制作动画，我们需要告诉plt将动画应用于给定的图形。然后plt将尝试更新该图及其所附的所有内容。如果您已经打开窗口，则动画仍将应用并起作用，但是您还将保留图形中最初绘制的内容（因此，我们应该关闭窗口并重新编码动画）。 plt不遵循每次执行一行与一次执行所有行相同的约定。在打开窗口之前和之后，plt的行为有所不同。

#Create xn and U. 

import matplotlib.pyplot as plt

figure = plt.figure()
axis   = figure.add_subplot(1,1,1)
axis.grid(True)
label  = 't = ' + str(tn[i][0])
plots  = axis.plot(xn,U[:,0],label=label)

def animate_function(frame):       
    frame %= 300                   #frame is an integer that counts from 0. 
    plots[0].set_ydata(U[:,frame]) #Change which globals you want. 
    return plots                   #Return the changed items so plt knows. 

#Tell plt to apply this animation function to your figure. 
#Tell plt to wait approximately 10ms per frame. 
#Tell plt to only update pixels that actually change (called blit). 
#Save to a global variable so plt doesn't get upset at you. 
ani    = animation.FuncAnimation(figure,animate_function,interval=10,blit=True)

#Now open the window and show the figure. 
figure.show()