如何获取单选按钮以更新直方图 Matplotlib Python

Question

I have a hard time getting radio buttons to update the histogram when using matplotlib.animation.

I'd like to show random sampling from a normal distribution. It starts with n=20. The animation works for n = 20. The radio buttons add a few more options: n=50, n=100, n=200.

Below are my codes. Thank you for your help!

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

n = 20
x = np.random.normal(-2.5, 1,size=n)

# create the function that will do the plotting, where curr is the current frame
def update(curr):
    # check if animation is at the last frame, and if so, stop the animation a
    if curr == n: 
        a.event_source.stop()
    plt.cla()
    bins = np.arange(-4, 4, 0.5)
    plt.hist(x[:curr], bins=bins)
    plt.axis([-7,5,0,30])
    plt.gca().set_title('Sampling the Normal Distribution')
    plt.gca().set_ylabel('Frequency')
    plt.gca().set_xlabel('Value')
    plt.annotate('n = {}'.format(curr), [3,25])   

#Plot    
fig = plt.figure()

#Create radio button
rax = plt.axes([0.01, 0.2, 0.15, 0.15])
radio = RadioButtons(rax, ('n=50', 'n=100', 'n=200'))

def samplesize(label):
    if label == 50:
        n=50
        a=animation.FuncAnimation(fig, update, interval=100)  
    elif label == 100:
        n=100
        a=animation.FuncAnimation(fig, update, interval=100)  
    else:        
        n=200
        a=animation.FuncAnimation(fig, update, interval=100)  
    plt.draw()  


radio.on_clicked(samplesize)    
a = animation.FuncAnimation(fig, update, interval=100)  
aax = plt.axes([0.3, 0.1, 0.6, 0.6])   
plt.show()

Answer 1

The code is adapted from this answer . For some reason you always have to click twice before the figure updates, but otherwise it should work fine.

# %matplotlib widget  # for jupyter notebook
import matplotlib.pyplot as plt
from matplotlib.widgets import RadioButtons
from matplotlib.animation import FuncAnimation
import numpy as np

n_max = 200
x_curr = np.random.normal(-2.5, 1, size=n_max)
bins = np.arange(-4, 4, 0.5)

def animate(i):
    ax.clear()
    ax.set_title('Sampling the Normal Distribution')
    ax.set_ylabel('Frequency')
    ax.set_xlabel('Value')
    ax.annotate('n = {}'.format(i), [3, 25])
    ax.axis([-7, 5, 0, 30])
    ax.hist(x_curr[:i], bins=bins)


anis = []
def on_click(event):
    n = int(event[2:])

    for ani in anis:
        ani.event_source.stop()
        anis.remove(ani)
        del ani

    print(n)
    ani = FuncAnimation(fig, animate, frames=n, repeat=False)
    anis.append(ani)
    fig.canvas.draw_idle()

fig = plt.figure()
ax = fig.subplots()

rax = plt.axes([0.01, 0.2, 0.15, 0.25])
radio = RadioButtons(rax, ('n=20', 'n=50', 'n=100', 'n=200'))
radio.on_clicked(on_click)
animate(20)
plt.show()