5

In gnuplot I can do this to get a square plot:

set size square

What is the equivalent in matplotlib? I have tried this:

import matplotlib
matplotlib.use('Agg')
import matplotlib.pyplot as plt
plt.rcParams['backend'] = 'TkAgg'
x = [0, 0.2, 0.4, 0.6, 0.8]
y = [0, 0.5, 1, 1.5, 2.0]
colors = ['k']*len(x)
plt.scatter(x, y, c=colors, alpha=0.5)
plt.axes().set_aspect('equal', adjustable='datalim')
plt.xlim((0,2))
plt.ylim((0,2))
plt.grid(b=True, which='major', color='k', linestyle='--')
plt.savefig('{}.png'.format(rsID), dpi=600)
plt.close()
plt.clf()

I get a square grid, but the plot itself is not square. How do I make the x range go from 0 to 2 and make the plot square? enter image description here

cb4
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tommy.carstensen
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2 Answers2

8

You can do it like this:

import matplotlib.pyplot as plt

fig, ax = plt.subplots()
x = [0, 0.2, 0.4, 0.6, 0.8]
y = [0, 0.5, 1, 1.5, 2.0]
colors = ['k']*len(x)
ax.scatter(x, y, c=colors, alpha=0.5)
ax.set_xlim((0,2))
ax.set_ylim((0,2))
x0,x1 = ax.get_xlim()
y0,y1 = ax.get_ylim()
ax.set_aspect(abs(x1-x0)/abs(y1-y0))
ax.grid(b=True, which='major', color='k', linestyle='--')
fig.savefig('test.png', dpi=600)
plt.close(fig)

enter image description here

elyase
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    At least by now (February 2020), you may use `set_aspect('equal')` to obtain the «same scaling from data to plot units for x and y» to offer the same result. – Buttonwood Feb 20 '20 at 16:58
3

Set the size in the figure: 

import matplotlib
matplotlib.use('Agg')
import matplotlib.pyplot as plt
plt.rcParams['backend'] = 'TkAgg'
x = [0, 0.2, 0.4, 0.6, 0.8]
y = [0, 0.5, 1, 1.5, 2.0]
colors = ['k']*len(x)
fig = plt.figure(figsize=(6,6)) # default is (8,6)
ax = fig.add_subplot(111, aspect='equal')
ax.scatter(x, y, c=colors, alpha=0.5)
ax.set_xlim((0,2))
ax.set_ylim((0,2))
ax.grid(b=True, which='major', color='k', linestyle='--')
Ben
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    Would the individual who down-voted the answer care to explain why? – Ben Jan 24 '15 at 03:58
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    It wasn't me, but I think what you did only sets the canvas size to equal, it doesn't set the actual plot area to being square. It can be messed up by the axis and tick labels and so on, because matplotlib will shrink the plot area to fit those things onto the canvas. – Ben Farmer Apr 27 '17 at 06:10