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Programming Tips

Strengthen your programming skills with tips and techniques from the experts

Programming Tips

t test for difference between group means in SAS

Rick WicklinJuly 3, 2017 0

Summary statistics and t tests in SAS

Students in introductory statistics courses often use summary statistics (such as sample size, mean, and standard deviation) to test hypotheses and to compute confidence intervals. Did you know that you can provide summary statistics (rather than raw data) to PROC TTEST in SAS and obtain hypothesis tests and confidence intervals?

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Analytics | Data Visualization | Programming Tips

Robert AllisonJune 29, 2017 0

Colors represent different things, in different cultures

Choosing great colors for a graph is sometimes the most difficult part. And here is yet another thing you need to worry about ... sometimes colors represent different things in different cultures! In this blog post, I improve a graphic to help you get a grasp on those color-to-culture relationships.

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Communications | Education | Travel

Machine Learning | Programming Tips

Chris Hemedinger

Chris HemedingerJune 28, 2017 0

Using Python to work with SAS Viya and CAS

One of the big benefits of SAS Viya is how approachable it is for programmers of other languages. You don't have to learn SAS in order to become productive quickly. We've seen a lot of interest from people who code in Python, maybe because that language has become known for

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Programming Tips

Rick WicklinJune 28, 2017 0

The average bootstrap sample omits 36.8% of the data

Suppose you roll six identical six-sided dice. Chance are that you will see at least one repeated number. The probability that you will see six unique numbers is very small: only 6! / 6^6 ≈ 0.015. This example can be generalized. If you draw a random sample with replacement from

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Learn SAS | Programming Tips

Ron CodyJune 27, 2017 0

How to perform an operation on all numeric or all character variables in a SAS data set

In a previous blog, I demonstrated a program and macro that could identify all numeric variables set to a specific value, such as 999. This blog discusses an immensely useful technique that allows you to perform an operation on all numeric or all character variables in a SAS data set.

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Learn SAS | Programming Tips

Ron CodyJune 26, 2017 0

Keeping your data set clean: Integrity constraints

When I teach my Data Cleaning course, the last topic I cover in the two-day course is SAS Integrity Constraints. I find that most of the students, who are usually quite advanced programmers, have never heard of Integrity Constraints (abbreviated ICs). I decided a short discussion on this topic would

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Data Visualization | Programming Tips

Warren F. KuhfeldJune 26, 2017 0

Advanced ODS Graphics: Range Attribute Maps

You can use a range attribute map to control the mapping of values in a continuous variable to colors. This post shows you how to use PROC SGPLOT to display multiple plots in the same graph and use range attribute maps.

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Programming Tips

Rick WicklinJune 26, 2017 0

Video: Create and use lists and tables in SAS/IML

My presentation at SAS Global Forum 2017 was "More Than Matrices: SAS/IML Software Supports New Data Structures." The paper was published in the conference proceedings several months ago, but I recently recorded a short video that gives an overview of using the new data structures in SAS/IML 14.2: If your

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Analytics | Data Visualization | Programming Tips

Robert AllisonJune 22, 2017 0

A map of country code top-level domains (ccTLD)

Here in the US, we typically use top level domains such as .com, .gov, and .org. I guess we were one of the first countries to start using web domains in a big way, and therefore we kind of got squatter's rights. As other countries started using the web, they

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Data Visualization | Programming Tips

Warren F. KuhfeldJune 22, 2017 0

Advanced ODS Graphics: Vector plots and adjusting point labels

A vector plot draws a line from one point in a graph to another point. In this post, I will show you how to create short vectors instead of vectors that emanate from the origin. I also show how to modify the positions of the vector labels.

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Advanced Analytics | Learn SAS | Programming Tips

Rick WicklinJune 21, 2017 0

Jackknife estimates in SAS

One way to assess the precision of a statistic (a point estimate) is to compute the standard error, which is the standard deviation of the statistic's sampling distribution. A relatively large standard error indicates that the point estimate should be viewed with skepticism, either because the sample size is small

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Analytics | Data Visualization | Programming Tips

Robert AllisonJune 20, 2017 0

Tabs -vs- Spaces: Which coders make more money?

There have been several polarizing topics throughout history, such as religion & political affiliation. And for software developers there's one more biggie ... tabs -vs- spaces! Which group is right? Perhaps the opinion of the better programmers should have more weight(?) Is there a metric we can use to determine whether

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Programming Tips

Russ TyndallJune 16, 2017 0

Using parameters within the macro facility

Have you ever written a macro and wondered if there was an easy way to pass values to the macro? You can by using macro parameters. Macro parameters enable you to pass values into the macro at macro invocation, and set default values for macro variables within the macro definition.

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Analytics | Data Visualization | Programming Tips

Robert AllisonJune 15, 2017 0

Map: Median age by country

If countries have a similar median age, does that mean they are also similar in other ways? My best guess at an answer is - probably. Perhaps if we plot the data on a map, we'll be able to see the answer more clearly. I first started thinking about this

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Government | Health Care

Data Visualization | Programming Tips

Robert AllisonJune 14, 2017 0

Bilingual job opportunities in the U.S.

When I was in college, I lived in the Alexander dorm, where each room had an American student and an International student. I learned a lot about the rest of the world, and I also heard a lot of different languages being spoken. I'm really impressed when I hear people

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Communications | Education | Government | Travel

Analytics | Programming Tips

Rick WicklinJune 14, 2017 0

Two ways to compute maximum likelihood estimates in SAS

In a previous article, I showed two ways to define a log-likelihood function in SAS. This article shows two ways to compute maximum likelihood estimates (MLEs) in SAS: the nonlinear optimization subroutines in SAS/IML and the NLMIXED procedure in SAS/STAT. To illustrate these methods, I will use the same data

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Data Visualization | Programming Tips

Warren F. KuhfeldJune 12, 2017 0

Customizing the Kaplan-Meier Plot

Customizing the Kaplan-Meier plot in assorted ways is so popular that we devote an entire chapter to it in the SAS/STAT documentation.

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Analytics | Programming Tips

Log-likelihood function for the binomial distribution

Rick WicklinJune 12, 2017 0

Two simple ways to construct a log-likelihood function in SAS

Maximum likelihood estimation (MLE) is a powerful statistical technique that uses optimization techniques to fit parametric models. The technique finds the parameters that are "most likely" to have produced the observed data. SAS provides many tools for nonlinear optimization, so often the hardest part of maximum likelihood is writing down

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Data Visualization | Learn SAS | Programming Tips

Robert AllisonJune 9, 2017 0

Star Trek (the original series) - the infographic!

If you were a fan of the original Star Trek television series, you probably remember lots of little details about the show. And you might even feel sorry for the people who don't get the clever references you make to things from the show. If you're that person, then you'll

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Sports & Entertainment

Programming Tips

Rick WicklinJune 7, 2017 0

The IFN function versus the IF-THEN/ELSE statement in SAS

I have previously discussed how to define functions that safely evaluate their arguments and return a missing value if the argument is not in the domain of the function. The canonical example is the LOG function, which is defined only for positive arguments. For example, to evaluate the LOG function

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Learn SAS | Programming Tips

Leonid BatkhanJune 6, 2017 0

Combine and conquer with SAS

The ancient political maxim “divide and conquer” (Lat. “dīvide et īmpera”) has been used for millennia in politics, sociology, and psychology, mainly to manipulate people. In the last two centuries, however, this principle has also been adopted by computer science. It is widely used in computer programming, primarily in computer

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Data Visualization | Learn SAS | Programming Tips

Robert AllisonJune 6, 2017 0

Graphing Ironman race data

This past weekend, I was a volunteer helping with an Ironman 70.3 race. I was really impressed & inspired by the athletes ... I was also excited about the quantity and variety of data generated by this type of race (compared to a regular marathon). And as a 'graph guy' I

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Sports & Entertainment

Learn SAS | Programming Tips

Ron CodyJune 6, 2017 0

Using regular expressions to verify the pattern of character data

Wait! Don't close this window. I understand that regular expressions can be very complicated (yes, there are many books on the subject), but some basic expressions to test patterns such as zip codes or telephone numbers are not that difficult. In addition, you can sometimes use Google to search for

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Data Visualization | Programming Tips

Bobbie WagonerJune 5, 2017 0

The new Data Pane in SAS Visual Analytics - It's painless!

Refining your data for effective reports is even easier in the 8.1 release of SAS Visual Analytics. In this blog post, I’ll take a look at the data pane, how it displays data from your active data source, and a few tasks that you might want to perform, such as

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Data Visualization | Learn SAS | Programming Tips

Robert AllisonJune 5, 2017 0

A medical dashboard for the Star Trek fans

As a kid who grew up in the 60s & 70s, I was a big fan of the original Star Trek TV series. And in the years since, I have seen lots of the Star Trek “technology” become a reality: cellphones, portable tablet computers, talking computers (Alexa/Siri), etc. But I

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Health Care | Life Sciences

Programming Tips

Rick WicklinJune 5, 2017 0

Runs in coin tosses; patterns in random seating

If you toss a coin 28 times, you would not be surprised to see three heads in a row, such as ...THHHTH.... But what about eight heads in a row? Would a sequence such as THHHHHHHHTH... be a rare event? This question popped into my head last weekend as I

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Analytics | Data Visualization | Programming Tips

Robert AllisonJune 2, 2017 0

How to 'stack the deck' for a better graph!

To stack the deck means to cheat or to fix something so a desired outcome is achieved. This term originated in card games, but can also be applied to other things. And here, I apply it (both metaphorically and literally) to creating a better graph! I recently saw the following

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Government | Manufacturing

Data Visualization | Programming Tips

Warren F. KuhfeldJune 1, 2017 0

Multipage Adverse Event Reports Using PROC SGPLOT

Did you know that you can make a graph extend across multiple pages? Making a multipage graph poses no problem for ODS Graphics---you simply use a BY variable to create page breaks. Most of the work involves deciding where to break pages and properly labeling continuations.

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Data Visualization | Programming Tips

Teri PatsilarasJune 1, 2017 0

Cascading Prompts as Report and Page Prompts in SAS Visual Analytics

There are several exciting new features available in SAS Visual Analytics 8.1 that I know will excite you; this blog will show you how you can now configure cascading prompts for the Report Prompt and Page Prompt areas! Prior to SAS Visual Analytics 8.1 there was a way to use parameters to configure cascading prompts for

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Learn SAS | Programming Tips

How to generate random numbers in SAS

Rick WicklinJune 1, 2017 0

How to choose a seed for generating random numbers in SAS

Last week I was asked a simple question: "How do I choose a seed for the random number functions in SAS?" The answer might surprise you: use any seed you like. Each seed of a well-designed random number generator is likely to give rise to a stream of random numbers,

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