Tag Archives: sas essentials

How to Use SAS – Lesson 6 – SAS Arithmetic and Variable Creation

This video series is intended to help you learn how to program using SAS for your statistical needs. Lesson 6 introduces the concept of SAS arithmetic in the DATA STEP. I discuss how one can add, subtract, divide, multiply, or create their own formulas for variables in the data. I also discuss using SAS arithmetic to create new variables based on mathematical transformations of old variables, which may sometimes aid in meeting the assumptions of statistical tests. Finally, I provide basic examples of each of these methods.

Helpful Notes:

1. SAS uses many of the same arithmetic operators to add, subtract, divide and multiply as other programming languages and basic algebra.

2. Arithmetic operations on variables affect the entire list of observations. So be careful in operating with existing variables and make new variables if you can afford to.

3. The varnum ;option on the PROC CONTENTS statement can allow you to see the variables listed in the order they were created.

Today’s Code:

data main;
input x y;
cards;
1 2
3 4
5 6
7 8
;
run;

proc print data=main;
run;

data new_main; set main;
a = x + y;
b = x – y;
c = x * y;
d = x / y;
e = x ** y;
f = ((x + y) * (x – y));
run;

proc contents data=new_main varnum;
run;

proc print data=new_main;
run;

-FAIR ;USE-
“Copyright Disclaimer Under Section 107 of the Copyright Act 1976, allowance is made for “fair use” for purposes such as criticism, comment, news reporting, teaching, scholarship, and research. Fair use is a use permitted by copyright statute that might otherwise be infringing. Non-profit, educational or personal use tips the balance in favor of fair use.”

Anayansi Gamboa has an extensive background in clinical data management as well as experience with different EDC systems including Oracle InForm, InForm Architect, Central Designer, CIS, Clintrial, Medidata Rave, Central Coding, OpenClinica Open Source and Oracle Clinical.

How to Use SAS – Lesson 2 – Creating Datasets on the Fly

This video series is intended to help you learn how to program using SAS for your statistical needs. Lesson 2 introduces some basic data step programming to define variables and specify their values for data sets containing one or more observations.

I also introduce two procedures: the PRINT procedure (PROC ;PRINT) to display the data contents in the OUTPUT window, and the CONTENTS procedure (PROC CONTENTS) to summarize the data set. Finally, I introduce the concept of libraries to show another method of inspecting the data set by physically opening it from the temporary WORK library.

Helpful Notes:

1. PROC PRINT – displays the entire data set by observation in the OUTPUT window
2. PROC CONTENTS – summarizes the properties of a data set, including an alphabetic listing of the variables and a count of the number of observations.
3. The assignment operator (“=”) directly specifies the value of a variable in the data step.
4. The INPUT statement defines one or more variables of our data set.
5. The CARDS statement specifies the values for each of the INPUT variables (in order).
6. It is a good rule of thumb to always pair the INPUT and CARDS statements together.
7. DON’T FORGET SEMI;COLONS! They end statements and without them, you will most certainly have errors arise.
8. If you have any errors, always, ALWAYS, ALWAYS check the LOG first!
9. Creating datasets “on-the-fly” just means you’re making a new dataset without bringing in the data from any other source.

Today’s Code:

data main;
input x y z;
cards;
1 2 3
7 8 9
;
run;

proc print data=main;
run;

proc contents data=main;
run;

-FAIR ;USE-
“Copyright Disclaimer Under Section 107 of the Copyright Act 1976, allowance is made for “fair use” for purposes such as criticism, comment, news reporting, teaching, scholarship, and research. Fair use is a use permitted by copyright statute that might otherwise be infringing. Non-profit, educational or personal use tips the balance in favor of fair use.”

Anayansi Gamboa has an extensive background in clinical data management as well as experience with different EDC systems including Oracle InForm, InForm Architect, Central Designer, CIS, Clintrial, Medidata Rave, Central Coding, OpenClinica Open Source and Oracle Clinical.

SAS Programming Tip: Formatted Input

This material is related to the type of content covered in the following courses:

SAS Programming Introduction: Basic Concepts
https://support.sas.com/edu/schedules.html?ctry=us&id=106

SAS Programming 1: Essentials
https://support.sas.com/edu/schedules.html?ctry=us&id=277

SAS Programming 2: Data Manipulation Techniques course
https://support.sas.com/edu/schedules.html?ctry=us&id=278

For more information about SAS programming, visit: https://support.sas.com/edu/courses.html?ctry=us

-FAIR USE-
“Copyright Disclaimer Under Section 107 of the Copyright Act 1976, allowance is made for “fair use” for purposes such as criticism, comment, news reporting, teaching, scholarship, and research. Fair use is a use permitted by copyright statute that might otherwise be infringing. Non-profit, educational or personal use tips the balance in favor of fair use.”