title: scatter plot does not plot all the points in the array + ternary library
body: <p>I am using the ternary library in python and trying to plot a scatter of points in the ternary plot.
  However it appears the below code only plots one single point for each of the 3 scatter calls made.
  Can you please advise     </p>
  
  <pre><code>    scale = 1
      figure, tax = ternary.figure(scale=scale)     
      tax.set_title("Scatter Plot", fontsize=20)          
      tax.boundary(linewidth=2.0)        
      tax.gridlines(multiple=5, color="blue")          
      # Plot a few different styles with a legend        
      points = np.array([df['73_prop']])        
      tax.scatter(points, marker='s', color='red', label="Outflows")      
      points = np.array([df['72_prop']])       
      tax.scatter(points, marker='D', color='green', label="HQLA")       
      points = np.array([df['74_prop']])        
      tax.scatter(points, marker='o', color='blue', label="Inflows")       
      tax.legend()       
      tax.ticks(axis='lbr', linewidth=1, multiple=5)     
  
      tax.show()      
  </code></pre>
  
  <p>Here is the plot i get right now</p>
  
  <p><a href="https://i.stack.imgur.com/lL13y.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/lL13y.png" alt="enter image description here"></a></p>
  
  <pre><code>    In [213]:points 
      Out[213]: 
      array([[ 0.47426346,  0.50559869,  0.50368877, ...,  0.65636812,
       0.56024801,  0.49020411]])
  </code></pre>
  
  <p>P.S. Am trying to mimic what's there on:
  <a href="https://github.com/marcharper/python-ternary#scatter-plots" rel="nofollow noreferrer">https://github.com/marcharper/python-ternary#scatter-plots</a></p>
  
  <p>I have also tried using certain for loop but hasn't helped.  </p>