动画无法在matplotlib上运行

Question

我试图在样本大小增加（从100到1000）时使形状的动画呈指数分布。还有一个滑块来配置分布的lambda参数和一个按钮来启动动画。

我的问题是，即使布局得到渲染，当我按下开始按钮时，不会出现动画。这里是我的尝试至今：

Editted把事情简单化，我在Python笔记本上运行它：

import numpy as np 
import matplotlib.pyplot as plt 
import matplotlib.animation as animation 
from matplotlib.widgets import Slider 

n0 = 100 
n1 = 1000 

#Create figure object 
fig, ax = plt.subplots(1,1) 
plt.subplots_adjust(bottom=0.3) 

#Create Sliders for parameters 
axlam = plt.axes([0.20, 0.05, 0.20, 0.03], facecolor=axcolor) 

slam = Slider(axlam, 'Exp lambda', 0, 5, valinit=1) 

#Default distributions 
dexp = np.random.exponential(1, n1) 

#Updates distributions when sliders are changed 
def updateDist(val): 
    lam = slam.val 
    dexp = np.random.exponential(lam, n1) 

slam.on_changed(updateDist) 

#updates plot on FuncAnimation call 
def update(curr): 
    if(curr == (n1-n0)): 
     a.event.source.stop() 
    plt.cla() 
    bins_exp = np.arange(0,4/slam.val,0.25) 
    ax.hist(dexp[:(n0+curr)],bins=bins_exp) 
    ax.set_title('Exp n={}'.format(n0+curr)) 

#Define Start button and function to start animation 
goax = plt.axes([0.8, 0.025, 0.1, 0.04]) 
button = Button(goax, 'Start', color=axcolor, hovercolor='0.975')  

a = None 
def start(event): 
    a = animation.FuncAnimation(fig,update,interval=100) 
button.on_clicked(start) 

Answer 1

你应该想到的功能的命名空间。

考虑

a = 0 
def f(): 
    a = 1 
f() 
print(a) # will print 0 

所以，你需要对实际工作的对象和他们的不是一些本地副本。

import numpy as np 
import matplotlib.pyplot as plt 
import matplotlib.animation as animation 
from matplotlib.widgets import Slider, Button 

n0 = 100 
n1 = 1000 

#Create figure object 
fig, ax = plt.subplots(1,1) 
plt.subplots_adjust(bottom=0.3) 

#Create Sliders for parameters 
axcolor = "skyblue" 
axlam = plt.axes([0.20, 0.05, 0.20, 0.03], facecolor=axcolor) 

slam = Slider(axlam, 'Exp lambda', 0, 5, valinit=1) 

#Default distributions 
dexp = [np.random.exponential(1, n1)] 

##Updates distributions when sliders are changed 
def updateDist(val): 
    lam = slam.val 
    dexp[0] = np.random.exponential(lam, n1) 

slam.on_changed(updateDist) 

#updates plot on FuncAnimation call 
def update(curr): 
    if(curr == (n1-n0)): 
     a.event.source.stop() 
    ax.clear() 
    bins_exp = np.arange(0,4/slam.val,0.25) 
    ax.hist(dexp[0][:(n0+curr)],bins=bins_exp) 
    ax.set_title('Exp n={}'.format(n0+curr)) 
    fig.canvas.draw_idle() 

#Define Start button and function to start animation 
goax = plt.axes([0.8, 0.025, 0.1, 0.04]) 
button = Button(goax, 'Start', color=axcolor, hovercolor='0.975')  

a = [0] 
def start(event): 
    a[0] = animation.FuncAnimation(fig,update,interval=100) 
button.on_clicked(start) 

plt.show()