title: matplotlib: Draw curved arrow that looks just like pyplot.arrow?
body: <p>I use <code>pyplot.arrow</code> do draw some straight arrows, e.g.,</p>
  
  <pre><code>import matplotlib.pyplot as plt
  import numpy as np
  
  v={}
  for i in range (1,4):
      v[i]=np.array([np.cos(-2*np.pi/3*i),np.sin(-2*np.pi/3*i)])
  
  plt.arrow(.85*(.05*v[2]+.95*v[1])[0],.85*(.05*v[2]+.95*v[1])[1],.85*.9*(v[2]-v[1])[0],.85*.9*(v[2]-v[1])[1],width=0,head_width=.03,head_length=.045,length_includes_head=True,color="black")
  plt.arrow(.85*(.05*v[3]+.95*v[2])[0],.85*(.05*v[3]+.95*v[2])[1],.85*.9*(v[3]-v[2])[0],.85*.9*(v[3]-v[2])[1],width=0,head_width=.03,head_length=.045,length_includes_head=True,color="black")
  plt.arrow(.85*(.05*v[1]+.95*v[3])[0],.85*(.05*v[1]+.95*v[3])[1],.85*.9*(v[1]-v[3])[0],.85*.9*(v[1]-v[3])[1],width=0,head_width=.03,head_length=.045,length_includes_head=True,color="black")
  
  plt.axes().set_xlim(-.5,1)
  plt.axes().set_ylim(-np.sqrt(3)/2,np.sqrt(3)/2)
  plt.axes().set_aspect(1)
  plt.show()
  </code></pre>
  
  <p>Now I want to also draw some arrows that have circular curvature instead of being straight. I see that I can achieve this with <code>pyplot.annotate()</code> or <code>patches.FancyArrowPatch</code> with <code>connectionstyle="arc3,rad=.5"</code> or so.</p>
  
  <p>But these arrows look completely different from the <code>pyplot.arrow</code>s and do not fit with the rest of my figures.  And I don't know how I could pass something like <code>connectionstyle</code> to <code>pyplot.arrow</code>. Is there a way to draw curved arrows that look exactly like those that I get from <code>pyplot.arrow</code>?</p>