title: How to connect dots where there are missing values?
body: <p>lets take this example:</p>
  
  <pre><code>       test=c(1,5,NA,5,4,1,NA,3,3,5,4,2)
  
        plot(test,type="l")
  </code></pre>
  
  <p>This will plot test but will not connect the dots.Is there a way we can ignore the NAs and connect the dots so we get pretty graph?</p>