ID season gasyear recordno 2401562901 Summer 19/20 1 2401562901 Winter 19/20 2 2401564310 Summer 19/20 1 2401564310 Summer 19/20 2 2402213802 Summer 19/20 1 2402213802 Summer 19/20 2 2402412909 Summer 19/20 1 2402412909 Summer 19/20 2 2416061809 Winter 19/20 1 2416061809 Summer 18/19 2     Hi, I want to create a column based on the following rules: it needs to look at each unique ID (there are only 2 rows per id).  is the season for record 1 'Summer' and season for record 2 'Summer' and are the gasyear for record 1 and record 2 the same if so it would give a flag 'Y' else 'N'   I have tried coding a few options and they don't work i tired the lag function but it doesn't work when going on to a new id    thanks  ... View more

  I want to be able to calculate the percentage change between the top value then the value below (CUML_VOL) and keep moving down a row and doing the same so for the first line I want to be able to calculate the difference between 66040.047 and 65895.855 as a starting point. i want the result to be displayed on the top row (but as you can see it stores it on the 2nd row and so on) and to keep working down until it gets to a new UC_POD_EXT  so in this case it would restart the calculation when it gets to UC_POD_EXT = 1346502   this is the code I tried:      data alldata; set alldata; retain percent_change; by uc_pod_ext; if last.uc_pod_ext then percent_change=0; else percent_change = lag(cuml_vol) - cuml_vol ; run;             ... View more