title: sort a data frame manually using non numeric column
body: <p>i have the following data frame</p>
  
  <pre><code>    dd &lt;- data.frame(b = c("High", "Medium", "Highest", "Low", "Not bad","Good", "V. Good"),
     x = c("C3", "C1", "C4", "N2", "C2", "N1","N4"), x = c("5", "2", "3", "6", "7", "5","7") )
  </code></pre>
  
  <p>so i want the data frame to be transformed using a manual order for the variable X.</p>
  
  <p>for example: that's the original one</p>
  
  <pre><code>1    High C3   5
  2  Medium C1   2
  3 Highest C4   3
  4     Low N2   6
  5 Not bad C2   7
  6    Good N1   5
  7 V. Good N4   7
  </code></pre>
  
  <p>but what i want is a new data frame to begin based on the value of X but not alphabetically, but randomly in an order which i chose e.g: </p>
  
  <pre><code>the first row has x=C1, the second have x=C2, the third have x=N4, ...etc
  </code></pre>
  
  <p>how this can be done??</p>
  
  <p>thank you</p>