title: Julia plotting: how to add both a single point and a list of points to a scatter plot
body: <p>If I plotted the following function:</p>
  <pre><code>f(x::Float64) = 4 - x^2
  scatter(c1p2e16, -3.0:0.1:3.0)
  </code></pre>
  <p>I would get:</p>
  <p><a href="https://i.stack.imgur.com/DzqkA.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/DzqkA.png" alt="enter image description here" /></a></p>
  <p>I have also made the following vector from 2 values:</p>
  <pre><code>val1 = 1                           &gt;&gt; 1
  val2 = median(map(c1p2e16, x))     &gt;&gt; 3
  vec = [val1,val2]             
  </code></pre>
  <p>I would like to add these values to the first plot, so that some 1,3 point would show up, like:</p>
  <p><a href="https://i.stack.imgur.com/6CXwr.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/6CXwr.png" alt="enter image description here" /></a></p>