title: object of type 'ListedColormap' has no len()
body: <p>I am trying to modify the code from this post </p>
  
  <p><a href="https://stackoverflow.com/questions/9081553/python-scatter-plot-size-and-style-of-the-marker">Python scatter plot. Size and style of the marker</a></p>
  
  <p>To give a different colour map. I have tried </p>
  
  <pre><code>import circlesDrawer as cdraw
  import matplotlib as mpl
  from pylab import *
  figure(figsize=(6,4))
  ax = subplot(aspect='equal')
  cmap = mpl.colors.ListedColormap(['royalblue', 'cyan',
                                    'yellow', 'orange'])
  #plot a set of circle
  a = [1,2,3]
  x = [1,3,4]
  y = [1,3,2]
  
  out=cdraw.circles(x,y,1,c=a,alpha=0.5,fc=cmap)
  colorbar()
  
  show()
  </code></pre>
  
  <p>but get the error </p>
  
  <pre><code>object of type 'ListedColormap' has no len()
  </code></pre>
  
  <blockquote>
    <p>I have no idea how to go about fixing this.</p>
  </blockquote>