title: combine matrixes of vectors with different length together in R
body: <p>I have two vectors,<code>a and b</code>. Both of them are of length <code>10</code>. Then I combined them together into <code>c</code>. There is another vector <code>d</code>, which is of length <code>20</code>. I got the error message when trying to combining them together. I would like to know is there any structure that can allow me to combine vectors with different length together.</p>
  
  <pre><code>&gt; a&lt;-rep(6,10)
  &gt; b&lt;-rep(8,10)
  &gt; c&lt;-cbind(a,b)
  &gt; d&lt;-rep(10,20)
  &gt; c
  &gt; x&lt;-cbind(c,d)
    Warning message:
    In cbind(c, d) :
    number of rows of result is not a multiple of vector length (arg 2)
  </code></pre>