title: Error in xgboost() in R
body: <p>I am trying to use xgboost(), but I am getting following error:</p>
  
  <pre><code>Error in xgb.DMatrix(data, label = label) : can not open file "0"
  
  If I traceback,
  
  traceback()
  4: .Call("XGDMatrixCreateFromFile_R", data, as.integer(FALSE), PACKAGE = "xgboost")
  3: xgb.DMatrix(data, label = label)
  2: xgb.get.DMatrix(data, label)
  1: xgboost(data = as.matrix(trainSet[, 1:13]), label = trainSet[, 
  "count"], max.depth = depth, nround = rounds, objective = "reg:linear", 
  verbose = 0) at #5
  </code></pre>
  
  <p>Any reason why I am getting the above error. I would appreciate any kind of help.</p>
  
  <p>Thanks in advance!</p>