How to make matplotlib auto scale y axis when using the draw

I have the follow sample code:

import matplotlib.pyplot as plt

# start with zeroed data

data_points = 10

fig, axs = plt.subplots()
x = list(range(data_points))
y = [0] * data_points
line, = axs.plot(x, y)

# initial render is required
fig.canvas.draw()

for i in range(10):
    y.pop(0)
    y.append(i / 10)

    line.set_ydata(y)
    axs.draw_artist(axs.patch)
    axs.draw_artist(line)

    fig.canvas.draw()

plt.show()

This simulates what I do in my app: I have a zeroed out data set, then I append values to the y data and redraw using the draw_artist.

I see here that the end result is what I get in my real app: the Y axis is scaled to fit the data that was appended to the y:

Y should end up going from 0 to 0.9, but it's stuck at what it looked like when the data was first drawn zeroed out.

How can I make the y axis update correctly in the sample above?

CodePudding user response：

Here you go the updated version of your code, you can achieve that by defining the ylim.

import matplotlib.pyplot as plt
import numpy as np

# start with zeroed data

data_points = 10

fig, axs = plt.subplots()
x = list(range(data_points))
y = [0] * data_points
line, = axs.plot(x, y)

# initial render is required
fig.canvas.draw()

for i in range(10):
    y.pop(0)
    y.append(i / 10)

    line.set_ydata(y)
    axs.draw_artist(axs.patch)
    axs.draw_artist(line)

    fig.canvas.draw()
plt.ylim(np.min(y),np.max(y))

plt.show()

This is what you will get: