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Learn SAS

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

Analytics | Learn SAS

Stephen MistlerFebruary 5, 2015 0

Solving Sudoku with SAS/IML – Part 2

Part 1 of this topic presented a simple Sudoku solver. By treating Sudoku as an exact cover problem, the algorithm efficiently found solutions to simple Sudoku problems using basic logic. Unfortunately, the simple solver fails when presented with more difficult Sudoku problems. The puzzle on the right was obtained from

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Advanced Analytics | Learn SAS

Rick WicklinFebruary 2, 2015 0

Detect empty parameters that are passed to a SAS/IML module

A SAS/IML programmer asked a question on a discussion forum, which I paraphrase below: I've written a SAS/IML function that takes several arguments. Some of the arguments have default values. When the module is called, I want to compute some quantity, but I only want to compute it for the

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Learn SAS

Sian RobertsJanuary 29, 2015 0

Why statisticians need strong communication skills

This year the American Statistical Association Conference on Statistical Practice (CSP) has some weighty themes including Big Data Prediction and Analysis and all of its exciting applications. But just as important is the theme Communication and Impact. Everyone knows that if you have a great idea or discovery but you

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Learn SAS

Rick WicklinJanuary 28, 2015 0

The relationship between skewness and kurtosis

In my book Simulating Data with SAS, I discuss a relationship between the skewness and kurtosis of probability distributions that might not be familiar to some statistical programmers. Namely, the skewness and kurtosis of a probability distribution are not independent. If κ is the full kurtosis of a distribution and

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Learn SAS | Programming Tips

Chris Hemedinger

Chris HemedingerJanuary 26, 2015 0

How to split one data set into many

Back in the day when the prison system forced inmates to perform "hard labor", folks would say (of someone in prison): "He's busy making little ones out of big ones." This evokes the cliché image of inmates who are chained together, forced to swing a chisel to break large rocks

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Rick WicklinJanuary 26, 2015 0

IF-THEN logic with matrix expressions

In the SAS DATA step, all variables are scalar quantities. Consequently, an IF-THEN/ELSE statement that evaluates a logical expression is unambiguous. For example, the following DATA step statements print "c=5 is TRUE" to the log if the variable c is equal to 5: if c=5 then put "c=5 is TRUE";

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Rick WicklinJanuary 22, 2015 0

What is an empty matrix?

At the beginning of my book Statistical Programming with SAS/IML Software I give the following programming tip (p. 25): Do not confuse an empty matrix with a matrix that contains missing values or with a zero matrix. An empty matrix has no rows and no columns. A matrix that contains

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Learn SAS | Programming Tips

Leonid BatkhanJanuary 21, 2015 0

SAS timer - the key to writing efficient SAS code

New Year to me is always a stark reminder of the inexorability of Time. In a day-to-day life, time is measured in small denominations - minutes, hours, days… But come New Year, and this inescapable creature – Time – makes its decisive leap – and in a single instant, we

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Rick WicklinJanuary 20, 2015 0

Five tips from Simulating Data with SAS

Data simulation is a fundamental technique in statistical programming and research. My book Simulating Data with SAS is an accessible how-to book that describes the most useful algorithms and the best programming techniques for efficient data simulation in SAS. Here are five lessons you can learn by reading it: Learn strategies

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Analytics | Learn SAS

Myles HannonJanuary 20, 2015 0

Panning for corporate gold requires gold standard skills

We now live in the era of ‘big data’, where data and its analysis have become crucial to the modern economy. In fact, "big data is the new 'corporate gold'," according to Mark Wilkinson, managing director of SAS UK & Ireland. A recent study by Cebr found that companies in

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Learn SAS

Rick WicklinJanuary 20, 2015 0

Finding matrix elements that satisfy a logical expression

A common task in SAS/IML programming is finding elements of a SAS/IML matrix that satisfy a logical expression. For example, you might need to know which matrix elements are missing, are negative, or are divisible by 2. In the DATA step, you can use the WHERE clause to subset data.

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Data sample from Cast Of Characters data set

SAS JediJanuary 17, 2015 0

Jedi SAS Tricks: DS2 & APIs - GET the data you are looking for

While perusing the SAS 9.4 DS2 documentation, I ran across the section on the HTTP package. This intrigued me because, as DS2 has no text file handling statements I assumed all hope of leveraging Internet-based APIs was lost. But even a Jedi is wrong now and then! And what better

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Analytics | Learn SAS

Catherine (Cat) Truxillo

Catherine (Cat) TruxilloJanuary 16, 2015 0

Learn how to maximize your data with SAS and Hadoop

Outside, the Cary, NC sky is gray and winds are blowing freezing rain, but a group of statisticians at SAS are channeling warm green hills and the soft, gold light of a California evening. Team conversations alternate between distributed processing, PROC IMSTAT and how many pairs of shorts to pack.

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Analytics | Learn SAS

Stephen MistlerJanuary 13, 2015 0

Solving Sudoku with SAS/IML – Part 1

Sudoku solvers have been written in SAS using a variety of methods (e.g., the DATA step, PROC SQL, and PROC CLP). Surprisingly, SAS/IML appears to have been overlooked for this purpose. On a challenge from a coworker, I wrote this blog post to demonstrate the flexibility of SAS/IML in the

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Advanced Analytics | Learn SAS

Rick WicklinJanuary 7, 2015 0

Compute the kth smallest data value in SAS

A SAS programmer recently posted a question to the SAS/IML Support Community about how to compute the kth smallest value in a vector of numbers. In the DATA step, you can use the SMALLEST function to find the smallest value in an array, but there is no equivalent built-in function

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Advanced Analytics | Learn SAS | Students & Educators

Kenneth SanfordDecember 19, 2014 0

Are there jobs for economists in analytics?

SAS will again be participating in the Allied Social Science Association annual meetings in January. This year the event will be held in Boston, and conference organizers expect more than 12,000 participants from a variety of backgrounds, including economics, finance and many other social sciences. One of the primary functions

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Advanced Analytics | Learn SAS

Rick WicklinDecember 15, 2014 0

Elementwise minimum and maximum operators

Like most programming languages, the SAS/IML language has many functions. However, the SAS/IML language also has quite a few operators. Operators can act on a matrix or on rows or columns of a matrix. They are less intuitive, but can be quite powerful because they enable you perform computations without

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Rick WicklinDecember 8, 2014 0

The direct product (Kronecker product) in SAS

There are many ways to multiply scalars, vectors, and matrices, but the Kronecker product (also called the direct product) is multiplication on steroids. The Kronecker product looks scary, but it is actually simple. The Kronecker product is merely a way to pack multiples of a matrix B into a block

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Learn SAS | Programming Tips

Jim SimonDecember 4, 2014 0

How to eliminate data error notes from the SAS log

A student in a SAS class recently asked if there were a way to eliminate data error notes from the SAS log and, instead, write them to a separate file. Of course there's a way! Here's a simple datastep. Notice the missing dollar sign to indicate the variable GENDER (M,

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Advanced Analytics | Learn SAS | Programming Tips

Compute minimum and maximum of rows and columns in SAS

Rick WicklinDecember 1, 2014 0

Compute maximum and minimum values for rows and columns in SAS

A common question on SAS discussion forums is how to compute the minimum and maximum values across several variables. It is easy to compute statistics across rows by using the DATA step. This article shows how to compute the minimum and maximum values for each observation (across variables) and, for

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Data Visualization | Learn SAS | Programming Tips

Leonid BatkhanNovember 28, 2014 0

Drill, baby, drill—using SAS to drill down through Google maps

➤ DISCLOSURE! In June 2018 Google introduced changes to the way it handles its Maps platform. They now require API key in order to embed a map, plus Google Maps "projects" must now be associated with a billing account. Unless these new Google rules are met, Google maps described in

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Rick WicklinNovember 24, 2014 0

Overview of new features in SAS/IML 13.1

SAS software contains a lot of features, and each release adds more.To make sure that you do not miss new features that appear in the SAS/IML language, the word cloud on the right sidebar of my blog contains numbers that relate to SAS or SAS/IML releases. For example, you can

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Rick WicklinNovember 17, 2014 0

The difference between RUN and CALL for SAS/IML subroutines

Have you ever noticed that some SAS/IML programmers use the CALL statement to call a subroutine, whereas others use the RUN statement? Have you ever wondered why the SAS/IML language has two statements that do the same thing? It turns out that the CALL statement and the RUN statement do

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Rick WicklinNovember 10, 2014 0

An efficient way to increment a matrix diagonal

I was recently asked about how to use the SAS/IML language to efficiently add a constant to every element of a matrix diagonal. Mathematically, the task is to form the matrix sum A + kI, where A is an n x n matrix, k is a scalar value, and I is the

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Learn SAS | Programming Tips

Rick WicklinNovember 3, 2014 0

Recent additions to the SAS/IML file-sharing community

It has been three months since the introduction of the SAS/IML File Exchange, so I thought I'd give a short update on recent submissions and activity. (Note: The File Exchange was merged into the SAS Community Library in 2022.) Users have submitted eight new articles. The application areas include experimental

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Learn SAS

Rick WicklinOctober 31, 2014 0

The next power of 2 and other tricks with logarithms

The other day I was doing some computations that caused me to wonder, "What is the smallest power of 2 that is greater than a given number?" The mathematics is straightforward. Given a number n, find the least value of k such that 2k ≥ n or, equivalently, k ≥

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Advanced Analytics | Learn SAS | Students & Educators

Polly Mitchell-GuthrieOctober 27, 2014 0

Unicorn hunting: finding data scientists outside traditional academic disciplines (part 2)

Finding people with the range of skills classified as data science can be a challenge, which is why some call them unicorns (do they really exist?), so I recently posted ten tips on finding unicorns. In my first post I elaborated on tips 1 and 2 (1. hire from an

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Analytics | Learn SAS

Darius BaerOctober 15, 2014 0

The SAS model factory – a big data solution

Do you have too many models to build, too many to manage, too few analytic resources or too much data? A Model Factory may be your answer. The mindset of analytics is changing. This represents the transformation from a “craftsman” dominated culture in which multiple weeks were spent cycling through

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Data Visualization | Learn SAS | Programming Tips

Leonid BatkhanOctober 13, 2014 0

Circling Google maps with SAS

➤ DISCLOSURE! In June 2018 Google introduced changes to the way it handles its Maps platform. They now require API key in order to embed a map, plus Google Maps "projects" must now be associated with a billing account. Unless these new Google rules are met, Google maps described in

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Learn SAS | Programming Tips

Charu ShankarSeptember 26, 2014 0

Help! Why does the WHERE clause choke on the INPUT function?

A student brought in this coding problem after her manager was struggling with this issue for a while. They played guessing games, but to no avail. Here’s what happened when they submitted data step and proc sql code using a WHERE clause with an INPUT function? data aileen; length hcn

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