title: Add new row to matrix one by one
body: <p>This is a simple problem, but for the life of me I cannot find the answer.</p>
  
  <pre><code>for (w in 1:47) {
      s &lt;- w + 1;
  
      while(s &lt; 49) {
          xx &lt;- wcc(x$codes[w,], x$codes[s,], 20)
          C = matrix(rbind(w,s,xx), nrow=1128, ncol=3, byrow=TRUE)
          s &lt;- s + 1;
      }
  }
  </code></pre>
  
  <p>in this loop, I want to put the XX into matrix C one by one.</p>