Hi Bill, Yes, you can write macros which operate as functions. For example, suppose you need to compute the study day of a visit, and you have both the visit date and first day of study med (Day 1) on the record. The following macro can be called as a function: %macro studyday (visdt, day1dt); visdt - day1dt + (visdt >= day1dt); %mend studyday; It could be invoked in a DATA step like this: data studydys; set olddata; studyday = %studyday(visdt, day1dt); run; Hope this helps, Nancy ... View more

Hi Jean-Sebastien, Try something like this (not tested): data new; merge fruits fruits (firstobs=2 rename=(fruit=fruit1)); run; Hope this helps, Nancy ... View more

Hi, You can't change the length of a variable once it has been created on the PDV. It sounds like at least one of the variables referenced in one of your LENGTH statements already exists in NEWV55. Try moving your LENGTH statements before the SET statement in your DATA step. Hope this helps, Nancy ... View more