title: How to exclude one column from data.table OR convert to data.table to MTS
body: <p>When using <code>data.table</code> is it possible to return all the columns except one, like in <code>data.frame</code>?</p>
  
  <p>If the answer is no, does anyone have an elegant way to transform a multiple time series <code>data.table</code> to a <code>zoo</code> or other time series object?</p>
  
  <p>Consider the following example:</p>
  
  <pre><code>library(data.table)
  library(zoo)
  
  ## DEFINE DATA
  set.seed(1)
  dt = data.table(
      mydates = as.Date("2012-01-01") + 1:9, 
      value1 = sort(rpois(9, 6)),
      value2 = sort(rpois(9, 6)),
      value3 = sort(rpois(9, 6)),
      value4 = sort(rpois(9, 6)),
      value5 = sort(rpois(9, 6)))
  
  ## CONVERT TO DATA FRAME
  df = as.data.frame(dt)
  
  ## CONVERT TO ZOO
  zooObj = zoo(df[,-1], df$mydates)
  
  ## EXAMPLE OF DESIRED RESULTS
  plot(zooObj, col=1:ncol(zooObj))
  </code></pre>
  
  <p>How would I do that without <code>df = as.data.frame(dt)</code>?</p>