PROC PRINT and PROC SORT

Sorting

PROC SORT reorders a data set by one or more BY variables. Use OUT= to write a sorted copy; without it, the input data set is replaced.

proc sort data=sashelp.class out=tallest;
   by descending height;
run;

proc print data=tallest(obs=5) noobs;
   var name sex height;
   format height 5.1;
run;

Name       Sex    Height

Philip      M      72.0
Alfred      M      69.0
Ronald      M      67.0
Mary        F      66.5
William     M      66.5

• DESCENDING applies to the variable right after it.
• Rows with equal values keep their original order (Mary comes before William in SASHELP.CLASS).
• You can't write into SASHELP — it's read-only, which is why OUT= is needed here.

Sort by several variables — the second breaks ties in the first:

proc sort data=sashelp.class out=by_sex_age;
   by sex descending age;
run;

NODUPKEY removes rows with duplicate BY values — handy for getting one row per key.

Printing

title 'Students aged 12';
proc print data=sashelp.class label noobs;
   where age = 12;
   var name height weight;
   label height = 'Height (in)' weight = 'Weight (lb)';
run;
title;

              Students aged 12

               Height    Weight
Name            (in)      (lb)

James           57.3      83.0
Jane            59.8      84.5
John            59.0      99.5
Louise          56.3      77.0
Robert          64.8     128.0

• VAR chooses and orders the columns.
• WHERE works in procedures too.
• LABEL shows descriptive column headings (PROC PRINT needs the LABEL option to use them).
• NOOBS hides the Obs column.
• TITLE stays in effect for every later step until you change it; title; clears it.

Totals by group

With data sorted by a variable, BY prints a separate section per group, and SUM adds totals:

proc sort data=sashelp.class out=sorted;
   by sex;
run;

proc print data=sorted noobs;
   by sex;
   var name weight;
   sum weight;
run;

Each section ends with the group total, and a grand total appears at the end: 811.0 pounds for the girls, 1,089.5 for the boys, and 1,900.5 in all.

Practice

Print the three lightest students — name, age, and weight — with a title.

proc sort data=sashelp.class out=lightest;
   by weight;
run;

title 'Three lightest students';
proc print data=lightest(obs=3) noobs;
   var name age weight;
   format weight 5.1;
run;
title;

    Three lightest students

Name      Age    Weight

Joyce      11     50.5
Louise     12     77.0
James      12     83.0