Xgb.cv and xgb.train - Why it is showing different train and test rmse values?

r
xgboost

#1

Hi,

In xgb.cv, getting rmse- train-rmse:0.325976+0.015203 test-rmse:1.786700+0.182155

Whereas, in xgb.train, its showing- test-rmse:15.264840 train-rmse:1.311399

Why there so much of difference?