code: def evalerror(preds, dtrain):
      labels = dtrain.get_label()
      return "error", float(sum(labels != (preds > 0.0))) / len(labels)
  
imports: import numpy
  import xgboost
label_desc: Use image node_id 3 for calling a global function with example usage: evalerror(preds, dtrain) and returns: str,  unknown