AFHood Group Blog The thoughtless yammerings of marketing junkies..

SAS DIF function – Comparing previous records

The SAS DIF function is another useful tool for operating on previous records.

Lets say you want to know the difference in the last year's revenue and this year's revenue. Here is the data:

Year          Revenue

2001           10,000

2002          30,000

2003          60,000

2004          100,000

data revenue1;

set revenue;

Rev_increase=dif1(revenue);

run;

Year          Revenue         Rev_increase

2001           10,000         .

2002          30,000         20,000

2003          60,000         30,000

2004          100,000       40,000

The dif functions compares the current record to the nth previous record.