是否可以将保存的图形保存在不同的范围内，而不需要绘制两次？

Question

假设我有一个非常大的数据集，需要很长时间来绘制。我想将它的两个数字保存在不同的范围内。在 GUI 中，我只需绘制一次并放大到所需的范围，然后重复以获得其他范围。如何在代码中自动执行此操作？

import numpy as np
import matplotlib.pyplot as plt

# Generate data
x = np.linspace(0, 2 * np.pi, 100)
y = np.sin(x)



# Create the first figure
plt.figure("fig1")

plt.scatter(x, y)  # suppose plot this will take a long time

plt.ylim(-1, 0)
plt.title("Figure 1: Sin(x) with y-range (-1, 0)")

# Save the first figure
plt.savefig("figure1.png")

# Create the second figure
plt.figure("fig2")

plt.scatter(x, y)  # is it possible to avoid this second plot? 

plt.ylim(0, 1)
plt.title("Figure 2: Sin(x) with y-range (0, 1)")

# Save the second figure
plt.savefig("figure2.png")

# Show the plots
plt.show()

Answer 1

matplotlib.pyplot

默认情况下保存以前绘制的数据，因此您无需重新绘制或重新创建图形

import numpy as np
import matplotlib.pyplot as plt

# Generate data
x = np.linspace(0, 2 * np.pi, 100)
y = np.sin(x)



# Create the first figure
plt.figure("fig1")

plt.scatter(x, y)  # suppose plot this will take a long time

plt.ylim(-1, 0)
plt.title("Figure 1: Sin(x) with y-range (-1, 0)")

# Save the first figure
plt.savefig("figure1.png")

plt.ylim(0, 1)
plt.title("Figure 2: Sin(x) with y-range (0, 1)")

# Save the second figure
plt.savefig("figure2.png")

# Show the plots
plt.show()