Matplotlib无法生成准确的滑块图

Question

我有以下方程式：

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y = ((b-6(x**k))/c)**(1/k)
k = 10/(6+c)

我知道当k>1时，y是凹的，当0

生成动态绘图的代码：

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

fig, ax = plt.subplots()
plt.subplots_adjust(left=0.25, bottom=0.25)
x = np.arange(0.0, 1.0, 0.001)
b_init = 1
c_init = 0
k = 10/(6+c_init)
delta_f = 1.0
y = ((b_init-6*(x**k))/c_init)**(1/k)
l, = plt.plot(x, y, lw=2)
ax.margins(x=0)

axcolor = 'lightgoldenrodyellow'
ax_b = plt.axes([0.25, 0.1, 0.65, 0.03], facecolor=axcolor)
ax_c = plt.axes([0.25, 0.15, 0.65, 0.03], facecolor=axcolor)

s_b = Slider(ax_b, 'b', 0.1, 18.0, valinit=b_init, valstep=delta_f)
s_c = Slider(ax_c, 'c', 0.1, 12.0, valinit=c_init)


def update(val):
    b = s_b.val
    c = s_c.val
    l.set_ydata(((b-6*(x**k))/c)**(1/k))
    fig.canvas.draw_idle()


s_b.on_changed(update)
s_c.on_changed(update)

resetax = plt.axes([0.8, 0.025, 0.1, 0.04])
button = Button(resetax, 'Reset', color=axcolor, hovercolor='0.975')


def reset(event):
    s_b.reset()
    s_c.reset()
button.on_clicked(reset)

def colorfunc(label):
    l.set_color(label)
    fig.canvas.draw_idle()

plt.show()

Answer 1

如果您正在使用juypter notebooks，您可以使用来自ipywidgets的小部件，如下所示。此外，如果您打印出b、c和k值，可能会对获得直觉有所帮助。

%matplotlib inline
import numpy as np
import matplotlib.pyplot as p
from ipywidgets import *

def y(x,b,c):
    k = 10/(6+c)
    print(f' b={b:.3f},c={c:.3f},k={k:.3f}')
    y = ((b-6*(x**k))/c)**(1/k)
    return y

def inter(b0,c0):
    y1=y(x,b0,c0)
    p.figure(figsize=(20,6))
    p.plot(x,y1)

dx=0.001    
x = np.arange(0, 1.0+dx, dx)  #  assuming you want to go to 1 inclusively

b0=widgets.FloatSlider(value=10,min=-1,max=18.0,step=0.01, 
                       description='b0', 
                       continuous_update=False,
                       readout_format='.3f',
                       layout=Layout(width='90%', height='20px'))

c0=widgets.FloatSlider(value=0.1,min=-1,max=12.0,step=0.01, 
                       description='c0', 
                       continuous_update=False,
                       readout_format='.3f',
                       layout=Layout(width='90%', height='20px'))

interact(inter, b0=b0,c0=c0);

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