title: In sympy plotting, how can I get a plot with a fixed aspect ratio?
body: <p>If I plot a circle with this snippet</p>
  
  <pre><code>from sympy import *
  x, y = symbols('x y')        
  p1 = plot_implicit(Eq(x**2 +y**2, 1),aspect_ratio=(1.,1.))
  </code></pre>
  
  <p>I will get a figure window like this one</p>
  
  <p><a href="https://i.stack.imgur.com/iPv7o.png" rel="noreferrer"><img src="https://i.stack.imgur.com/iPv7o.png" alt="enter image description here"></a></p>
  
  <p>Now the aspect ratio is not what I was expecting because I see an ellipse instead of a circle. Moreover, if I change the aspect ratio of the <strong>window</strong> (dragging the bottom-right corner of the window) I get also a change in the aspect ratio of the plot... The following image is what I get after dragging the corner in order to see a circle:</p>
  
  <p><a href="https://i.stack.imgur.com/UhlNx.png" rel="noreferrer"><img src="https://i.stack.imgur.com/UhlNx.png" alt="enter image description here"></a></p>
  
  <p>I would like to get a plot like the one you get in Matlab when you set <code>axis equal</code>, see <a href="http://it.mathworks.com/help/matlab/creating_plots/aspect-ratio-for-2-d-axes.html" rel="noreferrer">http://it.mathworks.com/help/matlab/creating_plots/aspect-ratio-for-2-d-axes.html</a> when you plot an ellipse</p>
  
  <p><a href="https://i.stack.imgur.com/cnvR5.png" rel="noreferrer"><img src="https://i.stack.imgur.com/cnvR5.png" alt="enter image description here"></a></p>
  
  <p>What am I missing?</p>
  
  <p>I am using Jupyter and the version of the notebook server is 4.1.0 and is running on: Python 2.7.11 |Anaconda 2.5.0 (64-bit)| (default, Dec  6 2015, 18:08:32) [GCC 4.4.7 20120313 (Red Hat 4.4.7-1)]</p>