title: Repeat the values of a row in matrix N number of times
body: <p>If I have a matrix in R that looks like the below:</p>
  
  <pre>
  1,3
  7,1
  8,2
  </pre>
  
  <p>How would I write code that creates a matrix like this:</p>
  
  <pre>
  1,3
  1,3
  1,3
  7,1
  8,2
  8,2
  </pre>
  
  <p>Where it repeats the row based on the right .column value?  Keep in mind I have a matrix that actually has a lot more rows than 2</p>