SAS: Assign Order Number by group and Calculating Accumulative Total in dataset using Retain Statement

Assigning group order for a set sequence of records.

data temp2;
retain order;
set temp1;
if _n_ =1 then order=1; /* _n_=1 identifies the first record.
else if var1 ne lag(var1) then order= sum(order,1);
else order = order ; 
run;

• Lag(var) the value of previous record in the var column.
• retain statement needs to be before the set statement.

Calculating the running total of weight and height for each record. The Retain statement retains the running total from the previous iteration to the next.

data one;
length AccWeight AccHeight 8.;
retain AccWeight 0 AccHeight 0;
set sashelp.class end=eof;
AccWeight = sum(AccWeight, weight);
AccHeight = sum(AccHeight, Height);
run;

The following codes deal with cumulative sum by the group where the variable for calculation contains null values. The variable regs is either 1 or 0 or null value. Sorting by the regs variable will force the the record with a regs value of 1 to be last record by the desired group.

Proc sort data= apps out = sortapp;
by id app_num regs;
run;
data sortapp1;
set sortapp;
by id app_num;
retain sumreg;
firstnum = first.a_num;
lastnum = last.a_num;
if first.a_num then sumreg = sum(regs);
else sumreg = sum(sumreg, regs);
run;