I have blogged about three different SAS/IML techniques that iterate over categories and process the observations in each category. The three techniques are as follows: Use a WHERE clause on the READ statement to read only the observations in the ith category. This is described in the article "BY-group processing
A key element of graphs used for analysis of safety data for clinical research is the inclusion of statistical data (or tables) about the study that are aligned with the x axis of the graph. A common example of this comes from the paper "Graphical Approaches to the Analysis of
The dictionary defines excellence as the quality or state of excelling or something in which one excels. Here at SAS, we get our definition of excellence from the stories we hear – stories from you, about you. These stories are here – in the SAS Circle of Excellence. The Circle of
Most management literature and studies posit that organizations with a clear mission and work objectives, understood by all levels of the organization, are the most productive. The key to that success is effectively communicating the mission, agreeing on key performance indicators and giving employees at all levels access to relevant
When you are working with probability distributions (normal, Poisson, exponential, and so forth), there are four essential functions that a statistical programmer needs. As I've written before, for common univariate distributions, SAS provides the following functions: the PDF function, which returns the probability density at a given point the CDF
"Welcome to the English summer." "In the US you have climate. In England we have Weather." These are just two of the familiar phrases I heard yesterday during the SAS Professionals Convention held at SAS UK in Marlow. The weather changed from sun to dark clouds to rain and even
Suppose that you have two data vectors, x and y, with the same number of elements. How can you rearrange the values of y so that they have the same relative order as the values of x? In other words, find a permutation, π, of the elements of y so
Update 24Nov2015: The methods in this post no longer work for Twitter, as Twitter has discontinued support for its "share count" API that was used within the Twitter share buttons. But the Facebook method still works, and I've described a method for counting LinkedIn shares on another post. As of
I've been working on a new book about Simulating Data with SAS. In researching the chapter on simulation of multivariate data, I've noticed that the probability density function (PDF) of multivariate distributions is often specified in a matrix form. Consequently, the multivariate density can usually be computed by using the
Spark lines, made popular by Edward Tufte, provide a way to visualize trends in a concise space, often inline with the rest of the narrative or data. Previously, I posted an article on Spark Plots in which I created different plot types, some of which included multiple graphs and data in each row. For such
Earlier this month SAS announced some really big news: DataFlux®, which has delivered market-leading data management solutions to customers for more than a decade, is now fully integrated into the SAS organization. The combination of the two brands helps customers build an integrated information management strategy supporting data management and
I just received this note in my inbox and wanted to make sure you also have all up-to-the-minute details about the SAS Professionals Convention: Dear SAS Professional, This year's SAS Professionals Convention is just over a week away. Although we've sold out of tickets for Tuesday, places are still available for
When I need to graph a function of two variables, I often choose to use a contour plot. A surface plot is probably easier for many people to understand, but it has several disadvantages when compared to a contour plot. For example, the following statements in SAS/IML Studio displays a
It's so important for companies to build what customers want rather than build a product and then convince the market to buy it. So I love it when I hear or read remarks like the one below - SAS has grown with me. That means that we have listened to
I received the following query regarding the RAND function in Base SAS: In SAS, is specifying 0 as a random number seed the same as not specifying a seed at all? The question concerns initializing the SAS random number stream by using the internal system clock. You can do this
We've all heard of her. A little blond girl with a penchant for trespassing, and very finicky preferences in mattresses and breakfast food. Unfortunately, Goldilocks isn't just part of a fairy tale, she is alive, well, and causing havoc throughout government. If you haven't made the connection yet, "bear" with
In 2011-2012, North Carolina became one of many states to restructure their educator evaluation system to incorporate student growth. The NC Department of Public Instruction commissioned the external expertise of WestEd to evaluate various growth models and recommend value-added technology that would help them best meet their mission of using meaningful evaluation to
For all of you whipper snappers (a loving term applied to generations younger than yourself) who haven't been around SAS since the beginning of time - like Phil Miller, Art Carpenter and Kathy Council have - you may not remember when SAS Users Groups conference proceedings weren't offered online. That's right
I often use the SAS/IML language for simulating data with certain known properties. In fact, I'm writing a book called Simulating Data with SAS. When I simulate repeated measurements (sometimes called replicated data), I often want to generate an ID variable that identifies which measurement is associated with which subject
Many of you know Mike Zdeb. He's a long-time SAS user and frequent presenter at SAS conferences. Zdeb is also a reviewer of many SAS Press books and author of his own SAS book, Maps Made Easy Using SAS. Zdeb contacted me after he read the May SAS Tech Report
The Swiss army knife is known for its versatility, with a variety of tools and blades to help you complete the task at hand. When you are creating graphics, you sometimes have a special feature you want to add, but you can't seem to find the right syntax "tool" to
Unlike many of you, data hasn’t always ruled my world. Though I took statistics and economics classes in college, I built my academic career around studying history and writing papers like “The Importance of the Family Dinner in Preserving the Italian Culture among Immigrants.” Don’t laugh; it earned me an
No matter what statistical programming language you use, be careful of testing for an exact value of a floating-point number. This is known in the world of numerical analysis as "10.0 times 0.1 is hardly ever 1.0" (Kernighan and Plauger, 1974, The Elements of Programming Style). There are many examples
According to Janet Stuelpner and Joseph Hantsch, the authors of the 2012 SAS Global Forum paper, One at a Time; Producing Patient Profiles and Narratives, patient profiles are used several ways depending upon the 'customer' need.
A reader wrote for help with a computational problem. He has a vector of length N and the vector contains integer values in the range [1, 120], which represent months for which events occurred over a 10-year period. The question is: what is the 24-month period for which the most
This is a third post on newspaper stories that I recently read. Today's post deals with science, politics, and rising sea levels. Incidentally, the title is a blatant reference to John Allen Paulos's brilliant book, A Mathematician Reads the Newspaper. Senate approves law that challenges sea-level science The NC legislature
Can you actually get something for nothing? With PROC SQL’s subquery and remerging features, yes, you can. Often there is a need to add group descriptive statistics such as group counts, minimum and maximum values for further by-group processing. Instead of first creating the group count, minimum or maximum values
This is my second post on some newspaper articles that I recently read. Today's post deals with academic fraud. Questions linger in academic fraud case Over the past year, the News and Observer has occasionally reported on a scandal at the University of North Carolina at Chapel Hill in which
This past weekend was Father's Day, so I took some time to relax and read the newspaper. I found several stories that suggested interesting statistical questions. Unfortunately, the data are not available for analysis. Nevertheless, the stories are worth sharing. Over the next few days, I'll post my thoughts on
Wizard Harry Potter makes magic just waving his wand around and shouting out spells. Using SAS Enterprise Guide (and you are welcome to shout out your own commands too) you can create some magic, allowing the Stored Process Wizard to code for you. On Step 2, the "Include code for"
