python matplotlib小部件不起作用

Question

现在我正在使用euler方法解决问题。我做了如下，但即使我移动slidr图表不会改变

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


for i in range(1,n):
    Nlist.append(Nlist[i-1]+dNlist[i-1]*deltat)
    Qlist.append(Qlist[i-1]+Qlist[i-1]*deltat)
    dNlist.append(Qlist[i]/(1+Qlist[i])*(1-Nlist[i]/Nmax)*Nlist[i])
    tlist.append(t0+i*deltat)
x=tlist
y=Nlist
fig=plt.figure()
l=fig.add_subplot(111)
fig.subplots_adjust(left=0.25, bottom=0.25)
l.plot(x,y,linewidth=2,color="red")
plt.xlabel("Value of t")
plt.ylabel("Value of N")
plt.title("Euler Method")


axcolor = 'lightgoldenrodyellow'
axQ0 = fig.add_axes([0.25, 0.15, 0.65, 0.03], axisbg=axcolor)
axNmax = fig.add_axes([0.25, 0.1, 0.65, 0.03], axisbg=axcolor)
axN0 = fig.add_axes([0.25, 0.05, 0.65, 0.03], axisbg=axcolor)

sQ0 = Slider(axQ0, 'init_Temp', 0, 0.1, valinit=Q0)
sNmax = Slider(axNmax, 'N_max', 1000, 100000, valinit=Nmax)
sN0 = Slider(axN0, "init_N",1,10,valinit=N0)

Answer 1

有关如何在Slider上使用Matplotlib page的示例。

在该示例中，可以看到update函数通过set_ydata()将新创建或更改的数据设置为表示绘图线的matplotlib.lines.Line2D对象。

在这里的代码中，您尝试将数据设置为matplotlib.axes._subplots.AxesSubplot对象，这当然不起作用。它实际上应该抛出错误，'AxesSubplot' object has no attribute 'set_ydata'。

因此，正确的代码应绘制到axes对象并保存生成的Line2D供以后使用。

ax=fig.add_subplot(111)
l, = ax.plot(x,y,linewidth=2,color="red")

为了完整起见，这里是完整的工作代码：

from __future__ import division
from matplotlib import pyplot as plt
from matplotlib.widgets import Slider

t0=0
Q0=0.001
tf=25
N0=5
Nmax=10000
dN0=Q0/(1+Q0)*(1-N0/Nmax)*N0
n=100
deltat=(tf-t0)/(n-1)

tlist=[t0]
Nlist=[N0]
Qlist=[Q0]
dNlist=[dN0]

for i in range(1,n):
    Nlist.append(Nlist[i-1]+dNlist[i-1]*deltat)
    Qlist.append(Qlist[i-1]+Qlist[i-1]*deltat)
    dNlist.append(Qlist[i]/(1+Qlist[i])*(1-Nlist[i]/Nmax)*Nlist[i])
    tlist.append(t0+i*deltat)
x=tlist
y=Nlist
fig=plt.figure()

#########
### Changes here: 
ax=fig.add_subplot(111)
fig.subplots_adjust(left=0.25, bottom=0.25)
l, = ax.plot(x,y,linewidth=2,color="red")
###########

plt.xlabel("Value of t")
plt.ylabel("Value of N")
plt.title("Euler Method")


axcolor = 'lightgoldenrodyellow'
axQ0 = fig.add_axes([0.25, 0.15, 0.65, 0.03], axisbg=axcolor)
axNmax = fig.add_axes([0.25, 0.1, 0.65, 0.03], axisbg=axcolor)
axN0 = fig.add_axes([0.25, 0.05, 0.65, 0.03], axisbg=axcolor)

sQ0 = Slider(axQ0, 'init_Temp', 0, 0.1, valinit=Q0)
sNmax = Slider(axNmax, 'N_max', 1000, 100000, valinit=Nmax)
sN0 = Slider(axN0, "init_N",1,10,valinit=N0)

def update(val):
    ini_Q = sQ0.val
    ini_Nmax = sNmax.val
    ini_N =sN0.val
    ini_dN=ini_Q/(1+ini_Q)*(1-ini_N/ini_Nmax)*ini_N
    tlist2=[t0]
    Nlist2=[ini_N]
    Qlist2=[ini_Q]
    dNlist2=[ini_dN]
    for i in range(1,n):
        Nlist2.append(Nlist2[i-1]+dNlist2[i-1]*deltat)
        Qlist2.append(Qlist2[i-1]+Qlist2[i-1]*deltat)
        dNlist2.append(Qlist2[i]/(1+Qlist2[i])*(1-Nlist2[i]/ini_Nmax)*Nlist2[i])
        tlist2.append(t0+i*deltat)
    l.set_ydata(Nlist2)
    fig.canvas.draw_idle()
sQ0.on_changed(update)
sNmax.on_changed(update)
sN0.on_changed(update)
plt.show()