How to realize the first-order difference of data in stata's time series analysis, it is best to write out the instructions. Thank you. . . . .
If it is a coherent time series
tsset？ date
gen？ d_price？ =? d.price //？ first difference
If it's not coherent
gen？ Date c? =? _n
tsset？ Date c
gen？ d_price？ =? D. price?