title: Matplotlib: RGBA values should be within 0-1 range
body: <p>I want to scatter some data points.</p>
  
  <p>I wrote:</p>
  
  <pre><code>sumy = sum(np.unique(y_train))+1
  yy = y_train/sumy
  
  
  plt.scatter(
      X_lda.iloc[:,0],
      X_lda.iloc[:,1],
      c=yy,
      cmap='rainbow')
  
  /usr/local/lib/python3.6/dist-packages/matplotlib/colors.py in to_rgba_array(c, alpha)
      277             result[mask] = 0
      278         if np.any((result &lt; 0) | (result &gt; 1)):
  --&gt; 279             raise ValueError("RGBA values should be within 0-1 range")
      280         return result
      281     # Handle single values.
  
  ValueError: RGBA values should be within 0-1 range
  </code></pre>
  
  <p>y_train is an integer between 0.0 to 9.0 and is considered to be the class of each data which I want to use as the color of that point. As you see, I even tried to normalize it between 0-1 as requested but it still throws an error. </p>