which function selects lags how to select lag order in ur.df in r what is p lag what is lag in.df what is the lag order in ur.df how to use ur.df to test stationarity how many lags does ur df test use what is lag order in ur.df test what is lag order in adf adf test lag order ur.df function lag what is the lag in adf.test which of the following functions will check stationarity? what is ur.df for adf what is the lag order in ur.df adf lag order what is the lag order in adf test when using adf.test which function selects the lag order using some criterion? which statement represents a lag order in ur which function in ur.df selects the lag order?