title: How to mark a point in a MATLAB plot?
body: <p>I have this plot</p>
  
  <p>[<a href="https://imgur.com/WTdmJ.jpg" rel="noreferrer">Full Resolution</a>]</p>
  
  <p><img src="https://imgur.com/WTdmJ.jpg" alt="alt text"></p>
  
  <p>I need to make a straight <strong>vertical</strong> line at a point on x axis that the <strong>user enters</strong> and <strong>show the coordinates of the intersection</strong> of that vertical line with my plot.</p>
  
  <p>How can this be done in MATLAB?</p>
  
  <p><strong>for example:</strong> the user enters 1020 then a straight vertical line will be drawn at 1020 that meets the plot at some point and the coordinates of that point will be shown somehow.</p>