title: Daily Average to monthly total in R
body: <pre><code>Date        DE      VE
  12/1/2016   93.387  0.095
  11/1/2016   77.968  0.095
  10/1/2016   65.184  0.095
  9/1/2016    63.984  0.095
  8/1/2016    67.657  0.095
  %m/%d/%Y
  </code></pre>
  
  <p>DE and VE are daily averages. How to convert from daily average to monthly total in R based on the actual days in that month? Total for 12/2016 =93.387*31. Need to calculate the monthly total for all 10*12 months from 2006-01 to 2016-12. </p>