SAS Merging and Creating New Variables

[kernsaf]

I am trying to merge two data sets and then create new variables from these data sets. In my library, I have two data sets (cross1 and long1) with the common variable MEDRNO. I'm trying to merge them and create two new variables (change_dilation and change_time). For these new variables, i want to take the difference between the first observation of dilation and all other observations of dilation. The same goes with change_time. However, I'm not getting any observations in my output. Any idea what I am doing wrong?

*question 1;

libname Hwk4 'C:\Users\USERABC\Desktop\Assignment 4';

run;

*question 2a;

proc sort data=hwk4.cross1;by MEDRNO;

proc sort data=hwk4.long1;by MEDRNO;

data merged;

merge hwk4.cross1 hwk4.long1;

by MEDRNO;

run;

*question 2b;

data hwk4;

if first.MEDRNO = 1 then do;

            base_dil = DILATION;

            t0 = time;

      end;

retain base_dil t0;

change_dilation = DILATION - base_dil;

change_time = time - t0;

run;

proc print;

run;

[Reeza]

What does the log say for starters.

For question 2b you dont have a set statement so you're not referring to any data set.

[SKK]

Some sample data would help.

[Chrishi]

For question 2b use set statement and use retain statement before set statement and try if still find problem then elobrate you issue using some dummy data.