title: insert elements in a vector in R
body: <p>I have a vector in R,</p>
  
  <pre><code>a = c(2,3,4,9,10,2,4,19)
  </code></pre>
  
  <p>let us say I want to efficiently insert the following vectors, b, and c,</p>
  
  <pre><code>b = c(2,1)
  d = c(0,1)
  </code></pre>
  
  <p>right after the 3rd and 7th positions (the "4" entries), resulting in,</p>
  
  <pre><code>e = c(2,3,4,2,1,9,10,2,4,0,1,19)
  </code></pre>
  
  <p>How would I do this efficiently in R, without recursively using <code>cbind</code> or so.</p>
  
  <p>I found a package <a href="http://rss.acs.unt.edu/Rdoc/library/R.basic/html/insert.html" rel="nofollow noreferrer">R.basic</a> but its not part of CRAN packages so I thought about using a supported version.</p>