Avoid distortring squares/circles in Matplotlib figure with fixed figsize-CodePudding

In a Matplotlib figure with aspect ratio 12:5, a square is drawn on ax and 4 circles on ax2. The 4 circles are then redrawn with different colors.

However, the square looks like a rectangle, and the circles look like ellipses.

Is it possible to maintain the figure aspect ratio without distorting the square and circles?

import matplotlib.pyplot as plt

def draw():
    
    ax.set_xlim(-1, 7)
    ax.set_ylim(-1, 7)
    
    ax2.set_xlim(-1, 7)
    ax2.set_ylim(-1, 7)
    ax2.set_xticks([])
    ax2.set_yticks([])

    p = plt.Rectangle((0,0), 5, 5)
    ax.add_patch(p)

    ax2.add_patch(plt.Circle((0,0), 0.1, color="r"))
    ax2.add_patch(plt.Circle((0,5), 0.1, color="r"))
    ax2.add_patch(plt.Circle((5,0), 0.1, color="r"))
    ax2.add_patch(plt.Circle((5,5), 0.1, color="r"))
    
def redraw():
    ax2.clear()

    ax2.set_xticks([])
    ax2.set_yticks([])
    ax2.set_xlim(-1, 7)
    ax2.set_ylim(-1, 7)

    ax2.add_patch(plt.Circle((0,0), 0.1, color="g"))
    ax2.add_patch(plt.Circle((0,5), 0.1, color="r"))
    ax2.add_patch(plt.Circle((5,0), 0.1, color="g"))
    ax2.add_patch(plt.Circle((5,5), 0.1, color="r"))
    
fig, ax = plt.subplots(figsize=(12, 5)) # needs to be non-square
ax2 = ax.twinx().twiny()
draw()
redraw()

CodePudding user response：

If you want no distortion, you need to change the limits on the x axis. You can change the xlimit according to the aspect ratio 12:5 = 2.4:

import matplotlib.pyplot as plt


def draw():

    ax.set_xlim(-1, 7 * 2.4)
    ax.set_ylim(-1, 7)

    ax2.set_xlim(-1, 7 * 2.4)
    ax2.set_ylim(-1, 7)
    ax2.set_xticks([])
    ax2.set_yticks([])

    p = plt.Rectangle((0, 0), 5, 5)
    ax.add_patch(p)

    ax2.add_patch(plt.Circle((0, 0), 0.1, color="r"))
    ax2.add_patch(plt.Circle((0, 5), 0.1, color="r"))
    ax2.add_patch(plt.Circle((5, 0), 0.1, color="r"))
    ax2.add_patch(plt.Circle((5, 5), 0.1, color="r"))


def redraw():
    ax2.clear()

    ax2.set_xticks([])
    ax2.set_yticks([])
    ax2.set_xlim(-1, 7 * 2.4)
    ax2.set_ylim(-1, 7)

    ax2.add_patch(plt.Circle((0, 0), 0.1, color="g"))
    ax2.add_patch(plt.Circle((0, 5), 0.1, color="r"))
    ax2.add_patch(plt.Circle((5, 0), 0.1, color="g"))
    ax2.add_patch(plt.Circle((5, 5), 0.1, color="r"))


fig, ax = plt.subplots(figsize=(12, 5))  # needs to be non-square
ax2 = ax.twinx().twiny()
draw()
redraw()

This yields the following