title: How to inverse a log2 transformation
body: <p>I have data in this form:</p>
  
  <pre><code>        ds           y
  1   2015-12-31 51737806366
  2   2016-01-01   451800500
  3   2016-01-04    48503189
  4   2016-01-06      221000
  5   2016-01-07   542483038
  6   2016-01-08   628189789
  7   2016-01-09   556762005
  8   2016-01-10   195672447
  9   2016-01-11   279202668
  10  2016-01-12   540234196
  11  2016-01-13  3403591404
  12  2016-01-14   610409176
  </code></pre>
  
  <p>the values on the <code>'y'</code> column represent income, money units. I made an exploratory plot of this data in its original form and found the plot not too useful, the visual of the data was not appropriate, so in order to improve my visualizations I applied a <code>log2()</code> transformation to the <code>'y'</code> column... it worked fine:</p>
  
  <pre><code>        ds        y
  1   2015-12-31 35.59050
  2   2016-01-01 28.75111
  3   2016-01-04 25.53158
  4   2016-01-06 17.75369
  5   2016-01-07 29.01500
  6   2016-01-08 29.22663
  7   2016-01-09 29.05249
  8   2016-01-10 27.54387
  9   2016-01-11 28.05674
  10  2016-01-12 29.00901
  11  2016-01-13 31.66441 
  </code></pre>
  
  <p>The problem now is that in order to complete my analysis I need to get the <code>'y'</code> values back to their original form. Is there anyway or implicit <code>R</code> function to reverse the <code>log2()</code> transformation I applied so I can get the original numbers back?</p>