ValueError: zu viele Werte zum Entpacken (sin/cos graph mit Python 2.7)

Question

Ich versuche sin und cos auf demselben Graphen mit Spyder (Python 2.7) zu plotten. Ich bin in der Lage eine winkenden sin Kurve mit diesem Code zu zeichnen:

import numpy as np 
from matplotlib import pyplot as plt 
from matplotlib import animation 

# First set up the figure, the axis, and the plot element we want to animate 
fig = plt.figure() 
ax = plt.axes(xlim=(0, 2), ylim=(-2, 2)) 
line, = ax.plot([], [], lw=2) 

# initialization function: plot the background of each frame 
def init(): 
    line.set_data([], []) 
    return line, 

# animation function. This is called sequentially 
def animate(i): 
    x = np.linspace(0, 2, 1000) 
    y = np.sin(2 * np.pi * (x - 0.01 * i)) 
    line.set_data(x,y)  
    return line, 

# call the animator. blit=True means only re-draw the parts that have changed. 
anim = animation.FuncAnimation(fig, animate, init_func=init, frames=200, interval=20, blit=True) 

Jetzt habe ich versucht, eine cos-Kurve zusammen mit der sin-Kurve hinzuzufügen und ich den Code geändert, indem sie in einer neuen Variable (z) unter der Animation Hinzufügen Funktion zum Zeichnen der Cosinus-Kurve. Dies ist, was ich geändert:

z = np.cos(2 * np.pi * (x - 0.01 * i)) 
line.set_data(x,y,x,z) 

Dies ist der neue Code zusammen ist:

import numpy as np 
from matplotlib import pyplot as plt 
from matplotlib import animation 

# First set up the figure, the axis, and the plot element we want to animate 
fig = plt.figure() 
ax = plt.axes(xlim=(0, 2), ylim=(-2, 2)) 
line, = ax.plot([], [], lw=2) 

# initialization function: plot the background of each frame 
def init(): 
    line.set_data([], []) 
    return line, 

# animation function. This is called sequentially 
def animate(i): 
    x = np.linspace(0, 2, 1000) 
    y = np.sin(2 * np.pi * (x - 0.01 * i)) 
    z = np.cos(2 * np.pi * (x - 0.01 * i)) 
    line.set_data(x,y,x,z)  
    return line, 

# call the animator. blit=True means only re-draw the parts that have changed. 
anim = animation.FuncAnimation(fig, animate, init_func=init, frames=200, interval=20, blit=True) 

aber ich erhielt:

Traceback (most recent call last): 
    File "C:\Python27\lib\site-packages\matplotlib\backend_bases.py", line 1290, in _on_timer 
    ret = func(*args, **kwargs) 
    File "C:\Python27\lib\site-packages\matplotlib\animation.py", line 925, in _step 
    still_going = Animation._step(self, *args) 
    File "C:\Python27\lib\site-packages\matplotlib\animation.py", line 784, in _step 
    self._draw_next_frame(framedata, self._blit) 
    File "C:\Python27\lib\site-packages\matplotlib\animation.py", line 803, in _draw_next_frame 
    self._draw_frame(framedata) 
    File "C:\Python27\lib\site-packages\matplotlib\animation.py", line 1106, in _draw_frame 
    self._drawn_artists = self._func(framedata, *self._args) 
    File "C:/Users/Keegan/.xy/startups/sinwavegraph.py", line 28, in animate 
    line.set_data(x,y,x,z)  
    File "C:\Python27\lib\site-packages\matplotlib\lines.py", line 561, in set_data 
    x, y = args 
ValueError: too many values to unpack 

Irgendwelche Vorschläge/Empfehlungen wäre sehr dankbar.

Answer 1

Man kann nicht set_data zu einer Zeile mit vier Argumente. Du brauchst eine andere Linie. Siehe folgende Lösung:

import numpy as np 
from matplotlib import pyplot as plt 
from matplotlib import animation 

# First set up the figure, the axis, and the plot element we want to animate 
fig = plt.figure() 
ax = plt.axes(xlim=(0, 2), ylim=(-2, 2)) 
line1, = ax.plot([], [], lw=2) 
line2, = ax.plot([], [], lw=2) 

# initialization function: plot the background of each frame 
def init(): 
    line1.set_data([], []) 
    line2.set_data([], []) 
    return [line1, line2] 

# animation function. This is called sequentially 
def animate(i): 
    x = np.linspace(0, 2, 1000) 
    y = np.sin(2 * np.pi * (x - 0.01 * i)) 
    z = np.cos(2 * np.pi * (x - 0.01 * i)) 
    line1.set_data(x, y) 
    line2.set_data(x, z) 
    return [line1, line2] 

# call the animator. blit=True means only re-draw the parts that have changed. 
anim = animation.FuncAnimation(fig, animate, init_func=init, frames=200, interval=20, blit=True) 
plt.show()