title: How to append a vector as a column in R matrix?
body: <p>Suppose I have a matrix similar as the one show below in R.</p>
  
  <pre><code>      [,1] [,2] [,3] 
  [1,]    2    4    3 
  [2,]    2    5    7
  </code></pre>
  
  <p>How can append a column to the front like below.</p>
  
  <pre><code>   [,1] [,2] [,3] [,4]
  [1,] 1   2    4    3 
  [2,] 1   1    5    7
  </code></pre>
  
  <p>Lastly, the matrix has many rows.</p>