Hi Arthur! Thanks very much for the suggestions. Best, Saurabh ... View more

Hi Patrick, Thank you. Your code works too! It is nice to know how different lines produce the same result because they make different use of similar logic. Thanks again. ... View more

Hi ballardw, What I meant is this, keep flagging or counting or whatever, until the want changes to a zero. Once a want changes to zero, it does not matter even if it changes to a want = 1 again for that particular id. Basically, I just want the first "set" of continuous want = 1 for any given id and ignore the want = 0 and the subsequent want = 1 (in sets or single). Ignore could mean drop the observation or just change the flag or stop counting or whatever (like above). The idea is the same. Sorry about the ambiguity. Thanks! PS: All ids always start with want = 1 in my dataset. ... View more

Hi Astounding, The code you gave totally works after adjusting it to my actual data. Basically there were also multiple dates with the ids but they did not matter as long as my indicator "want" had preselected my desirable observations. ... View more

Hi Jagadish, I could use your code by changing the end to if first.id then do ;     new_date=startdate;     flag=0;     end; I could do with just knowing what the difference between each date and the date of the previous row was. I later created indicators for the desired difference (1month, 1week etc.) Thanks! Hi Mit, Your code essentially gave the same result. Thanks. Hi Arthur, Your code will be super useful when the intervals are fixed. I am not sure how the intck function may be used when we might have a variable interval of choice. Thanks! ... View more

Hi Jagadish, Thank you for the suggestion. It works but only tells me when the date for a given id. It does not give me any control over what interval to choose. I want to know if the date changed and also if the date was for example, one week apart from the previous date. How do I raise a flag for that? Can we make the table look like this? id date          period 1 1/1/2001     0 1 1/1/2001     0 1 1/2/2002     395 1 1/2/2002     0 1 1/2/2003     365 1 1/2/2003     0 2 1/1/2005     695 2 1/1/2005     0 2 1/1/2005     0 2 1/2/2005     30 2 1/2/2005     0 2 1/3/2006     395 2 1/4/2006     30 the third column is days of difference between a given date and the previous date. ... View more

id date          interval1month 1 1/1/2001     0 1 1/1/2001     0 1 1/2/2002     0 1 1/2/2002     0 1 1/2/2003     0 1 1/2/2003     0 2 1/1/2005     0 2 1/1/2005     0 2 1/1/2005     0 2 1/2/2005     1 2 1/2/2005     0 2 1/3/2006     0 2 1/4/2006     1 Here, the third variable tells us if the interval between the date on that row and the immediately preceding date on the previous row was one month (1) or not (0), thus an indicator. Alternatively, a more generic solution could be id date          period 1 1/1/2001     0 1 1/1/2001     0 1 1/2/2002     365 1 1/2/2002     0 1 1/2/2003     365 1 1/2/2003     0 2 1/1/2005     695 2 1/1/2005     0 2 1/1/2005     0 2 1/2/2005     30 2 1/2/2005     0 2 1/3/2006     395 2 1/4/2006     30 where a variable simply counts the interval between a given date and the previous date in the preceding row. Thanks. ... View more

Hi Patrick, Thank you. It works. I can now use the properties of count to manipulate the observations. ... View more

I tried substr function. It is a longer way of doing this job. if substr(result, 1, 2) in("<=","=<",">=")then results=substr(result,3,10); else if substr(result,1,1)="<" then results=substr(result, 2,10); else results=result; results1=input(results,best12.); Your code totally works though. Thanks! ... View more