Programming Tips

Rick WicklinJuly 24, 2017 0

Difference operators as matrices

For a time series { y1, y2, ..., yN }, the difference operator computes the difference between two observations. The kth-order difference is the series { yk+1 - y1, ..., yN - yN-k }. In SAS, the DIF function in the DATA step computes differences between observations. The DIF function

Read More

English

Programming Tips

Kathryn McLawhornJuly 21, 2017 0

Selecting the top n% and bottom n% of observations from a data set

SAS® offers several ways that you can find the top n% and bottom n% of data values based on a numeric variable. The RANK procedure with the GROUPS= option is one method. Another method is The UNIVARIATE procedure with the PCTLPTS= option. Because there are several ways to perform this

Read More

English

Analytics | Data Visualization | Programming Tips

Robert AllisonJuly 20, 2017 0

Risks to US employment - automation and offshoring

Employment - that's been a hot topic here in the US lately. Many of the manufacturing jobs we had in past decades are gone now, and it would be great if there was a crystal ball to predict which jobs might be at risk of disappearing in the future. The

Read More

English

Government | Manufacturing

Data Visualization | Programming Tips

Robert AllisonJuly 19, 2017 0

Songs most frequently banned at weddings!

A lot of my friends seem to be getting married these days. Which got me thinking about wedding parties. Which then got me wondering what songs DJs do/don't play at weddings these days. And what was the outcome of my meandering thoughts ... a fun & interesting graph, of course! It

Read More

English

Sports & Entertainment

Learn SAS | Programming Tips

Lora D. DelwicheJuly 18, 2017 0

Organize your work with SAS® Enterprise Guide® Projects

Nowadays, whether you write SAS programs or use point-and-click methods to get results, you have choices for how you access SAS. Currently, when you open Base SAS most people get the traditional SAS windowing environment (aka Display Manager) as their interface. But it doesn’t have to be that way. If

Read More

English

Programming Tips

Chris HemedingerJuly 17, 2017 0

Customize your keys in SAS Enterprise Guide with AutoHotkey

SAS power users (and actually, power users of any application) like to customize their environment for maximum productivity. Long-time SAS users remember the KEYS window in SAS display manager, which allows you to assign SAS commands to "hot keys" in your SAS session. These users will invest many hours to

Read More

English

Analytics | Data Visualization | Programming Tips

Robert AllisonJuly 13, 2017 0

Are more women getting STEM degrees?

For the past several years, efforts have been under way to recruit more women into the STEM (science, technology, engineering, and math) fields. I recently saw an interesting graph showing the percentage of bachelor's degrees conferred to women in the US, and I wondered if I could tweak that graph

Read More

English

Education

Advanced Analytics | Programming Tips

Rick WicklinJuly 12, 2017 0

The bias-corrected and accelerated (BCa) bootstrap interval

I recently showed how to compute a bootstrap percentile confidence interval in SAS. The percentile interval is a simple "first-order" interval that is formed from quantiles of the bootstrap distribution. However, it has two limitations. First, it does not use the estimate for the original data; it is based only

Read More

English

Data Visualization | Programming Tips

Warren F. KuhfeldJuly 11, 2017 0

Basic ODS Graphics: Enabling, Selecting and Displaying Graphs

This post presents some basic aspects of ODS Graphics: enabling, selecting, and displaying graphs.

Read More

English

Programming Tips

Rick WicklinJuly 10, 2017 0

Bootstrap estimates in SAS/IML

I previously wrote about how to compute a bootstrap confidence interval in Base SAS. As a reminder, the bootstrap method consists of the following steps: Compute the statistic of interest for the original data Resample B times from the data to form B bootstrap samples. B is usually a large

Read More

English

Analytics | Programming Tips

Rick WicklinJuly 5, 2017 0

Test for the equality of two proportions in SAS

A SAS customer asked how to use SAS to conduct a Z test for the equality of two proportions. He was directed to the SAS Usage Note "Testing the equality of two or more proportions from independent samples." The note says to "specify the CHISQ option in the TABLES statement

Read More

English

Advanced Analytics | Programming Tips

Makoto Unemi (畝見 真)July 3, 2017 0

SAS Viyaでフーリエ変換

みなさま、こんにちは。 さて突然ですが、フーリエ変換ってご存知ですか？ おそらく物理学や経済学で波形データを分析したことのある方には馴染みがあるでしょうが、フーリエ変換は波形データを扱う手法です。 フーリエ変換では周期的な波形を、sin波やcos波の重ね合わせで説明しようというものです。 たとえば以下のような波形データは、どの時間にどのくらいの強さの波が流れているかを表現しています。 これをフーリエ変換することで、周波数と振幅で表すことができるようになります。 ↓　フーリエ変換！　↓   従来のSAS製品では波形データでフーリエ変換をする機能を提供していなかったのですが、SAS ViyaのSAS Forcastingという製品を使うことで、フーリエ変換を実施することができるようになりました。 SAS Viyaでできるのは短時間フーリエ変換（Short time Fourier transform）です。 今回はSAS Viyaでフーリエ変換を実施してみたいと思います。プログラミング言語はPythonを使用します。 まずは前準備として、必要なライブラリをインポートし、CAS sessionを作成します。 CAS sessionはSAS Viyaでデータ分析を行うCASというエンジンへ認証し、接続するものです。 # CAS sessionの用意 import swat   host = "localhost" port = 5570 user = "user" password = "p@ssw0rd"   mysession = swat.CAS(host, port, user, password)   #

Read More

Japanese

Programming Tips

Chris HemedingerJuly 3, 2017 0

Ten SAS Enterprise Guide program editor tricks

If you spend a lot of time in SAS Enterprise Guide (as I do), you probably get to know its features pretty well. But we don't always take the time to explore as we should, so there might be a few golden nuggets of editor knowledge that have escaped you

Read More

English

Programming Tips

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?

Read More

English

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.

Read More

English

Communications | Education | Travel

Machine Learning | Programming Tips

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

Read More

English

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

Read More

English

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.

Read More

English

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

Read More

English

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.

Read More

English

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

Read More

English

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

Read More

English

Communications

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.

Read More

English

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

Read More

English

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

Read More

English

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.

Read More

English

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

Read More

English

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

Read More

English

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

Read More

English

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.

Read More

English