title: R: If I have two matrices, one with nearly the same columns but mixed up. How can I effectively map the two matrices?
body: <p>Of the two matrices have one has i) the columns in different orders and ii) entire columns (every elements in the column) has the opposite different signs. An example would be</p>
  
  <pre><code>A = 1 2
      3 4
  
  b = 1.99 -1.02
      3.99 -2.99 
  </code></pre>
  
  <p>How can I re-order b such that it looks like:</p>
  
  <pre><code>b = 1.02 1.99
      2.99 3.99
  </code></pre>
  
  <p>Is there away to do this quickly in R?</p>