为什么我的图表没有绘制 linspace 生成的点？ （动画）

Question

When I remove linspace and plot points by typing them into a list by hand they are plotted just fine. However switch to linspace, and the points on the graph come up blank. What am I missing here? Printing the linspace lists show they are generating the values, but they don't seem to make the graph

import matplotlib.pyplot as plt
from matplotlib.animation import FuncAnimation
import numpy as np
%matplotlib qt

fig = plt.figure(figsize=(6,4))
axes = fig.add_subplot(1,1,1)
plt.title("Image That's Moving")

P=np.linspace(1,50,100)
T=np.linspace(1,50,100)

Position =[P]
Time = [T]
p2=[P]
t2=[T]


x,y=[],[]
x2,y2=[],[]


def animate(i):
    x.append(Time[i])
    y.append((Position[i]))
    x2.append(t2[i])
    y2.append((p2[i]))

    plt.xlim(0,100)
    plt.ylim(0,100)
    plt.plot(x,y, color="blue")
    plt.plot(x2,y2, color="red")



anim = FuncAnimation(fig, animate, interval=300)

Answer 1

It seems like you are facing a problem because of Position = [P] and Time = [T] .

Because numpy.linspace already returns an array, you don't need additional [] .

Here is a working example that is referenced from matplotlib tutorial .

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

def init():
    ax.set_xlim(0, 100)
    ax.set_ylim(0, 100)
    return ln,

def update(i):
    xdata.append(T[i])
    ydata.append(P[i])
    ln.set_data(xdata, ydata)
    return ln,

P = np.linspace(1, 50, 99)
T = np.linspace(1, 50, 99)

fig, ax = plt.subplots()
xdata, ydata = [], []
ln, = plt.plot([], [], 'ro')

ani = FuncAnimation(fig, update, frames=np.arange(len(T)),
                    init_func=init, blit=True)

plt.show()

Answer 2

It is not as easy as your written code and, also, not related to np.linspace , AIK. Combining Choi answer (or matplotlib example) with another related SO post we can do this job using some code like:

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

def init():
    ax1.set_xlim(0, 100)
    ax1.set_ylim(0, 100)
    ax2.set_xlim(0, 100)
    ax2.set_ylim(0, 100)
    return ln, ln2

def update(i, Position, Time, P2, T2, ln, ln2):
    x.append(Time[i])
    y.append(Position[i])
    x2.append(T2[i] + 10)
    y2.append(P2[i] + 10)
    ln.set_data(x, y)
    ln2.set_data(x2, y2)
    return ln, ln2

Position = P2 = np.linspace(1, 50, 100)
Time = T2 = np.linspace(1, 50, 100)

fig = plt.figure(figsize=(6, 4))
plt.title("Image That's Moving")
plt.xticks([])
plt.yticks([])
ax1 = fig.add_subplot(121)
ax2 = fig.add_subplot(122)
x, y, x2, y2 = [], [], [], []
ln, = ax1.plot([], [], 'bo')
ln2, = ax2.plot([], [], 'ro')

ani = FuncAnimation(fig, update, frames=Time.shape[0], fargs=(Position, Time, P2, T2, ln, ln2), init_func=init, blit=True)
ani.save('test.gif', writer='imagemagick', fps=30)