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
In Paul Allison’s own words, “It’s about time!” The first edition of his book on logistic regression came out in 1999, and since then, “there have been an enormous number of changes and enhancements to the SAS procedures for doing logistic regression and related methods.” Allison has incorporated those changes
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
If you're using JMP, please read on. This week's tip is from Professor Robert Carver and his popular book Practical Data Analysis with JMP. To read a free chapter and reviews of the book, visit Robert's author page. The following excerpt is from SAS Press author Robert Carver and his book "Practical Data Analysis with JMP" Copyright ©
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
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
If you communicate with an international audience, this tip is for you. John Kohl is a gifted linguistic engineer, technical writer and editor, and author of the award-winning The Global English Style Guide: Writing Clear, Translatable Documentation for a Global Market. At the beginning of the book, John introduces The Cardinal
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
SAS takes pride in the award-winning documentation we produce. From books to on-line help to embedded user assistance, we deliver the words that help our users understand how to use SAS software. However, as SAS applications and interfaces have become more sophisticated and interactive, it’s become more difficult to convey
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
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
We just published Gerhard Svolba’s Data Quality for Analytics Using SAS. When I first heard about it, I thought we’d have a tome covering such topics as standardizing data, cleaning it up, removing duplicates, and so on. However, as Gerhard says in his Introduction, “There are many aspects of data
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
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
This week's SAS tip comes from Michele Burlew and her book SAS Macro Programming Made Easy, Second Edition. Michele is the accomplished author of 7 SAS Press books and a much-respected SAS expert. You can learn more about Michele and read a free chapter from each of her books here. And if you like
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
My first thoughts on hearing that we’d be bringing out a new edition of JMP Start Statistics were, “But how do we improve on an already great book? What could be better?” JMP Start Statistics has been such a big success with JMP users for a long time, so the authors
So are you now dreaming big? Coming up with other ideas for how SAS Stored Processes can be leveraged in your installation of SAS? As I mentioned in last week's post, you could use OLAP cubes as a data source for your SAS Stored Process. Here is how I would
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
Don’t miss this list of most sought after books at PharmaSUG 2012. Last month’s conference featured several presentations from SAS authors and many of their books, along with industry-specific titles, were highly popular with attendees. The top 10 (in no particular order): Carpenter's Guide to Innovative SAS Techniques by Art
One of my new work friends says this frequently. But the statement is lost in his translation from Portuguese, it is not that he does not believe me, it is just that he has questions about how things happen so he can learn. I debate on which version of this
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
One of the most frequently asked questions we get in Publications is “I’m new to SAS. How do I get started?” We can always help with an answer to the question, but to do so we need to learn a little more about your plans for using SAS. Do you
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"
To celebrate special occasions like Father's Day, I like to relax with a cup of coffee and read the newspaper. When I looked at the weather page, I was astonished by the seeming uniformity of temperatures across the contiguous US. The weather map in my newspaper was almost entirely yellow
Gerhard Svolba is one of our busiest authors. His new book Data Quality for Analytics Using SAS just released and next Monday, June 18, he's participating in a live e-chat at 11 a.m. ET. In the meantime, I decided to feature our weekly SAS tip from Gerhard's first and also highly-regarded book Data Preparation
