FuncAnimation 如何在每次迭代后更新文本

Question

我正在尝试创建数字 pi 的蒙特卡洛估计的动画，对于每次迭代，我希望数值估计以文本的形式出现在图上，但之前的文本不会被删除并使值不可读。我尝试 Artist.remove(frame) 但没有成功。剧情是用Jupiter Notebook完成的

#Enable interactive plot
%matplotlib notebook
import math
from matplotlib.path import Path
from matplotlib.animation import FuncAnimation
from matplotlib.path import Path
import numpy as np
import matplotlib.pyplot as plt
from scipy.spatial import ConvexHull
from matplotlib.artist import Artist

N = 10000

#create necessary arrays
x = np.arange(0,N)
y = np.zeros(N)

#set initial points to zero
inHull = 0

def inCircle(point):
    #the function is given a point in R^n
    #returns a boolean stating if the norm of the point is smaller than 1.
    if np.sum(np.square(point)) <= 1:
        return True
    else:
        return False
    
#iterate over each point
for i in range(N):
    random_point = np.random.rand(2)*2 - 1
    
    #determine if the point is inside the hull
    if inCircle(random_point):
        inHull += 1
        
    #we store areas in array y.
    y[i]  = (inHull*4)/(i+1)
    

fig = plt.figure()
ax = plt.subplot(1, 1, 1)
data_skip = 20

def init_func():
    ax.clear()
    plt.xlabel('n points')
    plt.ylabel('Estimated area')
    plt.xlim((x[0], x[-1]))
    plt.ylim((min(y)- 1, max(y)+0.5))
    

    
def update_plot(i):
    ax.plot(x[i:i+data_skip], y[i:i+data_skip], color='k')
    ax.scatter(x[i], y[i], color='none')
    
    Artist.remove(ax.text(N*0.6, max(y)+0.25, "Estimation: "+ str(round(y[i],5))))
    ax.text(N*0.6, max(y)+0.25, "Estimation: "+ str(round(y[i],5)))


anim = FuncAnimation(fig,
                     update_plot,
                     frames=np.arange(0, len(x), data_skip),
                     init_func=init_func,
                     interval=20)
plt.show()

谢谢。

Answer 1

正如您在 init_func 中所做的那样，您应该使用 ax.clear() 清除每次迭代中的绘图。然后有必要稍微编辑绘图函数：

ax.plot(x[i:i+data_skip], y[i:i+data_skip], color='k')

最后，您必须使用 ax.set_xlim(0, N).

在每次迭代中修复 x 轴限制

完整代码

#Enable interactive plot
%matplotlib notebook
import math
from matplotlib.path import Path
from matplotlib.animation import FuncAnimation
from matplotlib.path import Path
import numpy as np
import matplotlib.pyplot as plt
from scipy.spatial import ConvexHull
from matplotlib.artist import Artist

N = 10000

# create necessary arrays
x = np.arange(0, N)
y = np.zeros(N)

# set initial points to zero
inHull = 0


def inCircle(point):
    # the function is given a point in R^n
    # returns a boolean stating if the norm of the point is smaller than 1.
    if np.sum(np.square(point)) <= 1:
        return True
    else:
        return False


# iterate over each point
for i in range(N):
    random_point = np.random.rand(2)*2 - 1

    # determine if the point is inside the hull
    if inCircle(random_point):
        inHull += 1

    # we store areas in array y.
    y[i] = (inHull*4)/(i + 1)

fig = plt.figure()
ax = plt.subplot(1, 1, 1)
data_skip = 20
txt = ax.text(N*0.6, max(y) + 0.25, "")

def init_func():
    ax.clear()
    plt.xlabel('n points')
    plt.ylabel('Estimated area')
    plt.xlim((x[0], x[-1]))
    plt.ylim((min(y) - 1, max(y) + 0.5))


def update_plot(i):
    ax.clear()
    ax.plot(x[:i + data_skip], y[:i + data_skip], color = 'k')
    ax.scatter(x[i], y[i], color = 'none')

    ax.text(N*0.6, max(y) + 0.25, "Estimation: " + str(round(y[i], 5)))
    ax.set_xlim(0, N)


anim = FuncAnimation(fig,
                     update_plot,
                     frames = np.arange(0, len(x), data_skip),
                     init_func = init_func,
                     interval = 20)

plt.show()

FuncAnimation 如何在每次迭代后更新文本

FuncAnimation how to update text after each iteration

python

math

animation

numpy

matplotlib

完整代码

动画