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Learn SAS

Learn about the latest tips, tutorials, upcoming events and certifications

Analytics | Data Visualization | Learn SAS

Rick WicklinJune 17, 2019 0

Influential observations in a linear regression model: The DFBETAS statistics

My article about deletion diagnostics investigated how influential an observation is to a least squares regression model. In other words, if you delete the i_th observation and refit the model, what happens to the statistics for the model? SAS regression procedures provide many tables and graphs that enable you to

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Learn SAS

Shannon Lasater

Shannon LasaterJune 11, 2019 0

Always wishing for more examples? Check out SAS’ new enhancement to the documentation

Sometimes the questions are complicated, and the answers are simple. - Dr. Seuss It seems appropriate that this blog include a Dr. Seuss quote about learning when discussing a new simple, yet deceivingly powerful initiative to help SAS customers with their journey to discover as much as possible about our

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Learn SAS | Programming Tips

Rick WicklinJune 10, 2019 0

5 reasons to use PROC FORMAT to recode variables in SAS

Recoding variables can be tedious, but it is often a necessary part of data analysis. Almost every SAS programmer has written a DATA step that uses IF-THEN/ELSE logic or the SELECT-WHEN statements to recode variables. Although creating a new variable is effective, it is also inefficient because you have to

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Learn SAS

Missy HannahJune 6, 2019 0

Interview with new SAS Press authors: Jim Blum and Jonathan Duggins

Want to learn SAS programming but worried about taking the plunge? Over at SAS Press, we are excited about an upcoming publication that introduces newbies to SAS in a peer-review instruction format we have found popular for the classroom. Professors Jim Blum and Jonathan Duggins have written Fundamentals of Programming

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Data Visualization | Learn SAS | Programming Tips

Rick WicklinJune 5, 2019 0

Plot a family of curves in SAS

A family of curves is generated by an equation that has one or more parameters. To visualize the family, you might want to display a graph that overlays four of five curves that have different parameter values, as shown to the right. The graph shows members of a family of

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Learn SAS | Programming Tips

Mike ZizziJune 4, 2019 0

SAS or Python? Why not use both? Using Python functions inside SAS programs

Two sayings I’ve heard countless times throughout my life are “Work smarter, not harder,” and “Use the best tool for the job.” If you need to drive a nail, you pick up a hammer, not a wrench or a screwdriver. In the programming world, this could mean using an existing

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Data Visualization | Learn SAS | Programming Tips

Rick WicklinJune 3, 2019 0

Graph wide data and long data in SAS

Statistical programmers and analysts often use two kinds of rectangular data sets, popularly known as wide data and long data. Some analytical procedures require that the data be in wide form; others require long form. (The "long format" is sometimes called "narrow" or "tall" data.) Fortunately, the statistical graphics procedures

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Analytics | Data Visualization | Learn SAS

Rick WicklinMay 30, 2019 0

Visualize interaction effects in regression models

Knowing how to visualize a regression model is a valuable skill. A good visualization can help you to interpret a model and understand how its predictions depend on explanatory factors in the model. Visualization is especially important in understanding interactions between factors. Recently I read about work by Jacob A.

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Learn SAS | SAS Events

Charu ShankarMay 30, 2019 0

New at SAS: Psychometric testing

Human behavior is fascinating. We come in so many shapes, sizes and backgrounds. Doesn’t it make sense that any tests we write also accommodate our wonderful differences?

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Data Visualization | Learn SAS

Scott HicksMay 21, 2019 0

Essentials of Map Coordinate Systems and Projections in Visual Analytics

If you spend any time working with maps and spatial data, having a fundamental understanding of coordinate systems and map projections becomes necessary. It’s the foundation of how spatial data and maps work. These areas invariably evoke trepidation and some angst, even in the most seasoned map professional. And rightfully

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Missy HannahMay 17, 2019 0

Do books count as endangered species?

As a publishing house inside of SAS, we often hear: “Does anyone want to read books anymore?” Especially technical programmers who are “too busy” to read. About a quarter of American adults (24%) say they haven’t read a book in whole or in part in the past year, whether in

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Analytics | Learn SAS

Rick WicklinMay 15, 2019 0

What is Kolmogorov's D statistic?

Have you ever run a statistical test to determine whether data are normally distributed? If so, you have probably used Kolmogorov's D statistic. Kolmogorov's D statistic (also called the Kolmogorov-Smirnov statistic) enables you to test whether the empirical distribution of data is different than a reference distribution. The reference distribution

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Data Visualization | Learn SAS | Programming Tips

PROC SGMAP SCATTER of Movie Locations

Kelly MillsMay 14, 2019 0

Geocoding US Street Addresses and Plotting Them with PROC SGMAP

I met many SAS programmers at the 2019 SAS Global Forum who geocode addresses using ArcGIS. Did you know that street address locations and other things can be found using the SAS GEOCODE procedure? PROC GEOCODE gives you coordinates for address, ZIP codes, ZIP+4 codes and cities. You can even

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Learn SAS | Programming Tips

Rick WicklinMay 13, 2019 0

Write to a SAS data set from inside a SAS/IML loop

In SAS/IML programs, a common task is to write values in a matrix to a SAS data set. For some programs, the values you want to write are in a matrix and you use the CREATE FROM/APPEND FROM syntax to create the data set, as follows: proc iml; X =

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Missy HannahMay 10, 2019 0

Happy National Limerick Day from SAS Press!

May 12th is #NationalLimerickDay! If you saw our Valentine’s Day poem, you know we at SAS Press love creating poems and fun rhymes, so check out our limericks below! So, what’s a limerick? National Limerick Day is observed each year on May 12th and honors the birthday of the famed

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Analytics | Learn SAS

Rick WicklinMay 1, 2019 0

Encodings of CLASS variables in SAS regression procedures: A cheat sheet

SAS regression procedures support several parameterizations of classification variables. When a categorical variable is used as an explanatory variable in a regression model, the procedure generates dummy variables that are used to construct a design matrix for the model. The process of forming columns in a design matrix is called

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Learn SAS | Programming Tips

Rick WicklinApril 29, 2019 0

The normal mixture distribution in SAS

Did you know that SAS provides built-in support for working with probability distributions that are finite mixtures of normal distributions? This article shows examples of using the "NormalMix" distribution in SAS and describes a trick that enables you to easily work with distributions that have many components. As with all

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Learn SAS | Students & Educators

Sean O'BrienApril 29, 2019 0

New AI offerings highlight many free ways to learn SAS

SAS Viya for Learners offers free access to AI and machine learning software for higher education teaching and learning, hosted in a new learning portal by SAS.

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Analytics | Learn SAS | SAS Events | Students & Educators

Trent SmithApril 28, 2019 0

SAS celebrates analytics talent, and those who shape it

A persistent analytics talent gap creates big opportunities for people who can wield analytics to help organizations make better decisions. Innovative analytics users and students who are rushing to fill that gap, and those who teach them, are being honored this week at SAS Global Forum. A special Sunday event

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Learn SAS | Programming Tips | SAS Administrators

Joe FurbeeApril 8, 2019 0

Launching the Developers Community in SAS Communities

As word spreads that SAS integrates with open source technologies, people are beginning to explore how to connect, interact with, and use SAS in new ways. More and more users are examining the possibilities and with this comes questions like: How do I code A, integrate B, and accomplish C?

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Learn SAS | Programming Tips

Rick WicklinApril 8, 2019 0

Use the FLOOR-MOD trick to allocate items to groups

Suppose you need to assign 100 patients equally among 3 treatment groups in a clinical study. Obviously, an equal allocation is impossible because the second number does not evenly divide the first, but you can get close by assigning 34 patients to one group and 33 to the others. Mathematically,

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Data Visualization | Learn SAS | SAS Events

Scott HicksApril 8, 2019 0

Why Maps matter: Lessons learned from London's 1854 Cholera outbreak

The catch phrase “everything happens somewhere” is increasingly common these days. That “somewhere” translates into a location on the Earth; a latitude and longitude. When one of these “somewhere’s” is combined with many other “somewhere’s”, you quickly have a robust spatial data set that becomes actionable with the right analytic

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Learn SAS | Programming Tips

Rick WicklinApril 3, 2019 0

Convergence in mixed models: When the estimated G matrix is not positive definite

I've previously written about how to deal with nonconvergence when fitting generalized linear regression models. Most generalized linear and mixed models use an iterative optimization process, such as maximum likelihood estimation, to fit parameters. The optimization might not converge, either because the initial guess is poor or because the model

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Learn SAS | Programming Tips

Rick WicklinApril 1, 2019 0

Matrix operations and BY groups

Many SAS procedures support the BY statement, which enables you to perform an analysis for subgroups of the data set. Although the SAS/IML language does not have a built-in "BY statement," there are various techniques that enable you to perform a BY-group analysis. The two I use most often are

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Data Visualization | Learn SAS

Scott HicksMarch 27, 2019 0

Creating custom region maps with SAS Visual Analytics

SAS Visual Analytics supports region maps for Country, US states, and provinces out-of-the-box. These work well for small scale maps covering the world, a continent, or a single country. However, other regions are often needed. Beginning in version 8.3, VA supports custom polygons to display regions such as sales territories,

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Data Visualization | Learn SAS

Rick WicklinMarch 20, 2019 0

Truncate response surfaces

An analyst was using SAS to analyze some data from an experiment. He noticed that the response variable is always positive (such as volume, size, or weight), but his statistical model predicts some negative responses. He posted the data and asked if it is possible to modify the graph so

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Data Visualization | Learn SAS | Programming Tips

Martin MinceyMarch 15, 2019 0

How to view or create ODS output without causing SAS® to stop responding or run slowly

SAS makes it easy for you to create a large amount of procedure output with very few statements. However, when you create a large amount of procedure output with the Output Delivery System (ODS), your SAS session might stop responding or run slowly. In some cases, SAS generates a “Not

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Learn SAS | Programming Tips

Rick WicklinMarch 11, 2019 0

How to detect SAS data sets that contain (or do not contain) character variables

A SAS programmer posted an interesting question on a SAS discussion forum. The programmer wanted to iterate over hundreds of SAS data sets, read in all the character variables, and then do some analysis. However, not every data set contains character variables, and SAS complains when you ask it to

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Data for Good | Learn SAS | Students & Educators

Sian RobertsMarch 7, 2019 0

Breaking down walls for science: SAS Press donates books to the world’s largest research methods library

In a move to combat "stataphobia" and foster excellence in statistics in developing countries, SAS Press last month donated 70 SAS Press titles to the Serageldin Research Library at the Library of Alexandria in Egypt. The library’s mission is to achieve statistical equity so that a student in Chad has

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