title: POSIXct and plyrmr
body: <p>Why do POSIXct objects not work with the plyrmr package? Here is my code:</p>
  
  <pre><code>filename2 &lt;- "/user/sgerony/mtcars"
  complex.function = function(x){
    as.data.frame(mutate(x,date.time=as.POSIXct("2014-01-01 03:15")))    
  }
  magic.wand(complex.function)
  
  mtcars %|% complex.function()
  </code></pre>
  
  <p>Result:</p>
  
  <pre><code>    mpg cyl  disp  hp drat    wt  qsec vs am gear carb           date.time
  1  21.0   6 160.0 110 3.90 2.620 16.46  0  1    4    4 2014-01-01 03:15:00
  2  21.0   6 160.0 110 3.90 2.875 17.02  0  1    4    4 2014-01-01 03:15:00
  3  22.8   4 108.0  93 3.85 2.320 18.61  1  1    4    1 2014-01-01 03:15:00
  4  21.4   6 258.0 110 3.08 3.215 19.44  1  0    3    1 2014-01-01 03:15:00
  </code></pre>
  
  <p>etc..</p>
  
  <pre><code>input(mtcars) %|% complex.function()
  </code></pre>
  
  <p>Result:</p>
  
  <pre><code>Error in mr(map = map, reduce = reduce, combine = combine, vectorized.reduce,  : 
    hadoop streaming failed with error code 1
  </code></pre>
  
  <p>Thank you!</p>