The most common way to read observations from a SAS data set into SAS/IML matrices is to read all of the data at once by using the ALL clause in the READ statement. However, the READ statement also has options that do not require holding all of the observations in
Congratulations to Curt Hinrichs and Chuck Boiler! Their book, JMP Essentials: An Illustrated Step-by-Step Guide for New Users, has won an Award of Distinguished Technical Communication in this year’s International Summit Awards presented by the Society for Technical Communication. The award goes to a project that “applies the principles of
In last week's article on how to create a funnel plot in SAS, I wrote the following comment: I have not adjusted the control limits for multiple comparisons. I am doing nine comparisons of individual means to the overall mean, but the limits are based on the assumption that I'm
Greg Nelson and Neil Howard presented a lunchtime keynote talk at SAS Global Forum, and they produced this video, "Revenge of the Semi-Colon People", to go along with it. The video features many people from the SAS community, including customers and SAS employees. Watch it and see if you know
The log transformation is one of the most useful transformations in data analysis. It is used as a transformation to normality and as a variance stabilizing transformation. A log transformation is often used as part of exploratory data analysis in order to visualize (and later model) data that ranges over
I've been walking around the last few days with what looks like a dollop of chocolate syrup or grape jelly on my chin. Alas, it is just a bruise from getting elbowed in the mouth at basketball last Thursday night. (Church leagues may be the only dirtier place to play
One of the advantages of programming in the SAS/IML language is its ability to transform data vectors with a single statement. For example, in data analysis, the log and square-root functions are often used to transform data so that the transformed data have approximate normality. The following SAS/IML statements create
When I encounter an ERROR, WARNING, or NOTE in my SAS log that I don't understand, my first recourse is to ask my friend (we'll call him "Google") what it could mean. I copy the entire message (or at least 5 or 6 consecutive words from it) into the search
Last week I showed how to create a funnel plot in SAS. A funnel plot enables you to compare the mean values (or rates, or proportions) of many groups to some other value. The group means are often compared to the overall mean, but they could also be compared to
A major news item this week is the New York Department of Health's labeling of childen's games like Kickball, Wiffleball, Freeze Tag, Red Rover, and Steal the Bacon as dangerous. (Apparently Spin the Bottle, Truth or Dare, and Doctor are still ok?) Is this the continuing wussification of American youth?
This is a guest post from Jodi Blomberg, a Principal Technical Architect at SAS. She has over 12 years of experience in data mining and mathematical modeling, and has developed analytic models for many government agencies including child support enforcement, insurance fraud, intelligence led policing, supply chain logistics and adverse
In our last installment, we learned that some information is not really necessary. When facilities management dyed the toilet water purple to remind us it is non-potable, it didn't affect my earlier decision not to drink out of the toilet. Sometimes the information we receive as forecasters is not really
Last week I presented the GSR algorithm, a statistical model of a riffle shuffle. In the model, a deck of n cards is split into two parts according to the binomial distribution. Each piece has roughly n/2 cards. Then cards are dropped from the two stacks according to the number
In a previous post, I showed how to read data from a SAS data set into SAS/IML matrices or vectors. This article shows the converse: how to use the CREATE, APPEND, and CLOSE statements to create a SAS data set from data stored in a matrix or in vectors. Creating
Unless you’ve been living under a rock, you’ve heard about the budget problems running rampant across all levels of government. Federal, State and Local Governments are all facing historic budget shortfalls due to the economic crisis and decreased tax receipts. This has led to a much closer examination of services
On March 28 I had the pleasure of moving to our new office building on the scenic SAS campus in Cary, NC. This aesthetic and functional structure houses the sales, marketing, and SAS executive management offices, as well as a generously appointed Executive Briefing Center for hosting our visiting customers.
In a previous blog post, I showed how you can use simulation to construct confidence intervals for ranks. This idea (from a paper by E. Marshall and D. Spiegelhalter), enables you to display a graph that compares the performance of several institutions, where "institutions" can mean schools, companies, airlines, or
I recently returned from a five-day conference in Las Vegas. On the way there, I finally had time to read a classic statistical paper: Bayer and Diaconis (1992) describes how many shuffles are needed to randomize a deck of cards. Their famous result that it takes seven shuffles to randomize
This morning I delivered a talk to visiting high school students at the SAS campus. The topic: using SAS to analyze Twitter content. Being teenagers, high school students are well familiar with Twitter. But this batch of students was also very familiar with SAS, as they all have taken SAS
Linking business analytics to economic value is a hard problem. Despite all the smarts that get poured into models, it's hard to tie them to financial measures such as profitability. And, because of that, it's hard to justify investment in analytics. Need headcount? Sorry, try again. Need tools? Sorry, can't
"Convergence after 23 iterations to (1.23, 4.56)." That's the message that I want to print at the end of a program. The problem, of course, is that when I write the program, I don't know how many iterations an algorithm requires nor the value to which an algorithm converges. How
At the beginning of 2011, I heard about the Dow Piano, which was created by CNNMoney.com. The Dow Piano visualizes the performance of the Dow Jones industrial average in 2010 with a line plot, but also adds an auditory component. As Bård Edlund, Art Director at CNNMoney.com, said, The daily
In a previous blog post about computing confidence intervals for rankings, I inadvertently used the VAR function in SAS/IML 9.22, without providing equivalent functionality for those readers who are running an earlier version of SAS/IML software. (Thanks to Eric for pointing this out.) If you are using a version of
When comparing scores from different subjects, it is often useful to rank the subjects. A rank is the order of a subject when the associated score is listed in ascending order. I've written a few articles about the importance of including confidence intervals when you display rankings, but I haven't
The federal government is more aggressively pursuing health care fraud, and helping the states do the same, by proposing funding changes and investing in new technologies. A newly proposed rule would allow 90% Federal Financial Participation (FFP) for data mining initiatives in state Medicaid Fraud Control Units (MFCU’s). Another proposed
Suppose that friendship is a 2-way relationship: Either two people are friends with each other, or they are not. (By this definition, X cannot be a friend of Y if Y is not a friend of X. Also, you cannot be a friend of yourself -- no matter how attractive
Yesterday I was in the Big Room for the rehearsal of the Technology Connection, the part of SAS Global Forum where SAS shows off its wares: what's been released recently and what's coming. I believe that customers are going to love what they see. And just about every product that
In my article on computing confidence intervals for rankings, I had to generate p random vectors that each contained N random numbers. Each vector was generated from normal distribution with different parameters. This post compares two different ways to generate p vectors that are sampled from independent normal distributions. Sampling
While talking to fellow SAS users at SAS Global Forum 2011 this week, I'll be discussing how SAS programmers can "play" with social media data that they can access on Facebook and Twitter. I always refer people to my blog for more information, and so I've prepared this blog post
This morning Rick Wicklin announced his (hostile?, nah...) takeover of the technical blog space at SAS. I'll admit that it took me by surprise when I awoke in Siberia this morning. It's so cold here; I can't feel my fingers as I type. This is probably a punishment for the
