title: How to create a scatter plot legend with only one symbol for each label?
body: <p>How can I create a scatter plot legend without two symbols showing up each time? I can understand why you'd want this when you're joining symbols by lines, but for a pure scatter plot, all I want in the legend is one example of the symbol. This plot from a previous stackoverflow post shows the kind of thing I mean:</p>
  
  <p><img src="https://i.stack.imgur.com/p2FR2m.png" alt="enter image description here"></p>