I encountered a wonderful survey article, "Robust statistics for outlier detection," by Peter Rousseeuw and Mia Hubert. Not only are the authors major contributors to the field of robust estimation, but the article is short and very readable. This blog post walks through the examples in the paper and shows
This morning I logged onto my e-mail at 6:45 AM to learn that SAS was ranked as the No. 3 Best Company to Work For. No. 3 is not as high as No. 1. But it's very, very close. Perhaps even barely distinguishable, in the larger scheme of things. I
An issue that SAS/GRAPH users have wrestled with in the past has been how to put tick marks at irregular intervals on their axes. In PROC GPLOT, if you specify irregular intervals using the ORDER option on the AXIS statement, the procedure’s axis kicks into a “discrete” mode, where the
The Winter 2012 issue of Foresight is now available. Here is Editor Len Tashman's preview: --------------------------- Our last two issues featured Steve Morlidge’s Guiding Principles for managing an organization’s forecasting process. You can see the summary table of these principles on page 31. With this issue, we continue their development
In my recent article on simulating Buffon's needle experiment, I computed the "running mean" of a series of values by using a single call to the CUSUM function in the SAS/IML language. For example, the following SAS/IML statements define a RunningMean function, generate 1,000 random normal values, and compute the
Cities and counties are responsible for building and maintaining the infrastructure to support a broad range of services. Local governments must develop and implement multiyear capital projects plans that provide infrastructure for things such as jails, courts, public office buildings, streets, bridges, parks, athletic complexes and community centers, water treatment
Once again I rediscovered something that I once knew, but had forgotten. Fortunately, this blog is a good place to share little code snippets that I don't want to forget. I needed to compute the diagonal elements of a product of two matrices. In symbols, I have an nxp matrix,
Here at SAS Publishing, we’ve started the new year off with a bang, particularly when it comes to conferences. We’re attending a number of new shows in addition to the usual lineup this year. Visit our booth, meet our authors, check out our new and forthcoming titles, and talk with
The SAS/IML READ statement has a few convenient features for reading data from SAS data sets. One is that you can read all variables into vectors of the same names by using the _ALL_ keyword. The following DATA steps create a data set called Mixed that contains three numeric and
In the Star Wars movie, Obi-wan could just wave his hand, mutter a few words, and the stormtroopers would "move along". How the power of the Force makes ridding yourself of problematic characters so much easier! I recently was invited to become an alternate instructor for Ron Cody’s SAS Business
A recent question on a SAS Discussion Forum was "how can you overlay multiple kernel density estimates on a single plot?" There are three ways to do this, depending on your goals and objectives. Overlay different estimates of the same variable Sometimes you have a single variable and want to
It is "well known" that the pairwise deletion of missing values and the resulting computation of correlations can lead to problems in statistical computing. I have previously written about this phenomenon in my article "When is a correlation matrix not a correlation matrix." Specifically, consider the symmetric array whose elements
A’s in the front, Z’s in the back. How many of us grew up sitting in alphabetical order next to the same few classmates throughout school? While this is a quick and efficient way to learn student names, which is no easy task, it is not the most effective way
Before there was CNN or FOX News, people used to get their news from SAS. At least, that's how I imagine that people kept themselves informed. What else can explain the existence of the NEWS= system option, which helps SAS admins to surface the must-know information to the SAS community?
In my article on Buffon's needle experiment, I showed a graph that converges fairly nicely and regularly to the value π, which is the value that the simulation is trying to estimate. This graph is, indeed, a typical graph, as you can verify by running the simulation yourself. However, notice
Dear Miss SAS Answers, In PROC REPORT can I use one calculated (computed) variable in the calculation of another computed variable? In the example below, I’m trying to use the value of the Bonus column to calculate the Total column: compute Bonus; Bonus =sal.sum*0.05; endcomp; compute Total; total=sum(sal.sum, Bonus.sum); endcomp;
Have you taken the Myers-Briggs Type Indicator (MBTI) assessment? It is a psychological test wherefrom you are classified on Extraversion vs. Introversion, Sensing vs. Intuition, Thinking vs. Feeling, and Judging vs. Perceiving. I, along with roughly 15% of the population, come out an ISTJ or "Guardian Inspector" (the single largest
During one week in December, two separate transportation agencies within the federal government made two major announcements. First, the National Highway Traffic Safety Administration (NHTSA) – the government agency responsible for guiding traffic safety initiatives on the nation’s highways announced that crash fatalities had declined to record low rates. Just
A recent post on the SAS website shows the SAS Annual Revenue History. It would be interesting to see how we could create such a graph using SG procedures, and how we could add more information and interest in the presentation. So, I started with the basic informaiton on the annual revenues provided,
In the R programming language, you can use a negative index in order to exclude an element from a list or a row from a matrix. For example, the syntax x[-1] means "all elements of x except for the first." In general, if v is a vector of indices to
Following up on the theme of graphs commonly used in many applications, here is another one that displays a horizontal bar chart with multiple data columns aligned with the bars. Recently at WUSS, a user stopped by asking how to create just such a graph. While this user wanted something more complex
Buffon's needle experiment for estimating π is a classical example of using an experiment (or a simulation) to estimate a probability. This example is presented in many books on statistical simulation and is famous enough that Brian Ripley in his book Stochastic Simulation states that the problem is "well known
In the immortal words of Britney Spears: Oops! I did it again. At least, I'm afraid that I did. I think I might have helped a SAS student with a homework assignment, or perhaps provided an answer in preparation for a SAS certification exam. Or maybe it was a legitimate
Local governments are not immune to the rising demand for more accountability in government run services and programs, and the expenditure of public funds. Elected officials and citizens alike want to know what these programs accomplish for the public investment made. To date, the response to these questions and demands has been
Let us ring in the new year with something simple and useful. A recent question by a user over the holidays motivated this article on what is likely a commonly used graph. We want to compare the preformance of two categories along with a third measure. This could be something like "How
Hello, 2012! It's a New Year and I'm flushed with ideas for new blog articles. (You can also read about The DO Loop's most popular posts of 2011.) The fundamental purpose of my blog is to present tips and techniques for writing efficient statistical programs in SAS. I pledge to
At the beginning of 2011, I made four New Year's resolutions for my blog. As the year draws to a close, it's time to see how I did: Resolution: 100 blog posts in 2011: Completed. I blew by this goal by posting 165 articles. I recently compiled a list of
Is there anything you'd like to tell your management? Of course, in the spirit of the holiday season, I mean is there anything you'd like to tell your management that isn't anatomically impossible? If so, please join me and Ryan Rickard, Sr. Supply Chain Manager at Newell Rubbermaid, for our
Ron Cody and his supremely helpful book Learning SAS by Example close out our weekly SAS Author's Tip of 2011. Ron Cody is a household name in the SAS user community. And he deserves the moniker on his license plate of "SASMAN". Just mentioning Ron's name at user conferences incites awe. Sometimes
Lots of the visitors to this blog arrive here by way of Google search (welcome!). Thanks to search engines and a few well placed keywords, the same older posts (let's call them "timeless topics") seem to attract the most traffic from year to year. I hope that the searchers find
