Python plots graph into button instead of figure - python-3.x

Question

I'm a total beginner to python (started some days ago).
This little program is supposed to draw sinus waves, and the buttons at the bottom should increase / decrease the frequency of the plotted sinus. But my program plots the sinus into the button, for whatever reason. Where is the mistake? I've tried so much already... Thanks in advance ❤
import numpy as np
import matplotlib.pyplot as plt
from matplotlib.widgets import Button
class Function:
def __init__(self, amplitude, frequency):
self.amplitude = amplitude
self.frequency = frequency
self.time = np.arange(0.0, 1.0, 0.001)
self.signal= amplitude*np.sin(2*np.pi*frequency*self.time)
def status(self):
print("The frequency is: ", self.frequency)
print("The amplitude is: ", self.amplitude)
def setFrequency(self, frequency):
self.frequency = frequency
def setAmplitue(self, amplitude):
self.amplitude = amplitude
def show(self):
plt.plot(self.time, self.signal, linewidth = 2)
plt.ylabel("Sinus")
plt.xlabel("x")
pass
func = Function(1, 20)
func.show()
def IncreaseFrequency(event):
global func
if (func.frequency < 100):
func.setFrequency(func.frequency + 10)
else:
func.setFrequency(10)
func.show()
plt.draw()
pass
def LowerFrequency(event):
global func
if (func.frequency > 10):
func.setFrequency(func.frequency - 10)
else:
func.setFrequency(100)
func.show()
plt.draw()
pass
buttonIncrSize = plt.axes([0.7, 0.01, 0.1, 0.05])
buttonLowerSize = plt.axes([0.81, 0.01, 0.1, 0.05])
buttonIncrFreq = Button(buttonIncrSize, 'Next')
buttonLowerFreq = Button(buttonLowerSize, 'Previous')
buttonIncrFreq.on_clicked(IncreaseFrequency)
buttonLowerFreq.on_clicked(LowerFrequency)
plt.show()

Answer 1

First what looks kind of weird is that after lowering or increasing your frequency, you never update the self.signal, which should change if your frequency changes.
Secondly, from what I could see on this link, plt.plot returns an Line2D object which you can use to set the y data on your plot using line2D.set_ydata(new_ydata).
After changing the y data, just update the plot using plt.draw() and that should work.
EDIT: Indeed I didn't have access to my PC but ran this now and didn't work. After some search:
import numpy as np
import matplotlib.pyplot as plt
from matplotlib.widgets import Button
import matplotlib
class Function:
def __init__(self, amplitude, frequency):
self.amplitude = amplitude
self.frequency = frequency
self.time = np.arange(0.0, 1.0, 0.001)
self.signal = amplitude * np.sin(2 * np.pi * frequency * self.time)
def status(self):
print("The frequency is: ", self.frequency)
print("The amplitude is: ", self.amplitude)
def setFrequency(self, frequency):
self.frequency = frequency
self.signal = self.amplitude * np.sin(2 * np.pi * frequency * self.time)
def setAmplitude(self, amplitude):
self.amplitude = amplitude
self.signal = self.amplitude * np.sin(2 * np.pi * frequency * self.time)
def show(self):
plt.cla()
plt.plot(self.time,self.signal,lw=2)
plt.draw()
plt.ylabel("Sinus")
plt.xlabel("x")
def IncreaseFrequency(event):
global func
if (func.frequency < 100):
func.setFrequency(func.frequency + 10)
else:
func.setFrequency(10)
func.show()
def LowerFrequency(event):
global func
if (func.frequency > 10):
func.setFrequency(func.frequency - 10)
else:
func.setFrequency(100)
func.show()
fig, ax = plt.subplots()
func = Function(1, 20)
func.show()
buttonIncrSize = plt.axes([0.7, 0.01, 0.1, 0.05])
buttonLowerSize = plt.axes([0.81, 0.01, 0.1, 0.05])
buttonIncrFreq = Button(buttonIncrSize, 'Next')
buttonLowerFreq = Button(buttonLowerSize, 'Previous')
buttonIncrFreq.on_clicked(IncreaseFrequency)
buttonLowerFreq.on_clicked(LowerFrequency)
plt.sca(fig.axes[0])
plt.show()
Main change being the plt.sca(fig.axes[0]) which allows to select the current axis for plt. When you run plt.axes() it sets the current axes of plt to the button, hence subsequently plotting your graph in that button.
Also added plt.cla() which clears the current plotting area.