I love dogs. Not to the extent that Rick Santorum has to be concerned. And not to the extent of actually having a dog as a pet. But man-dog love has become an issue in the 2012 US presidential campaign, and I thought The BFD readers should know my stance
I previously described how to use Mahalanobis distance to find outliers in multivariate data. This article takes a closer look at Mahalanobis distance. A subsequent article will describe how you can compute Mahalanobis distance. Distance in standard units In statistics, we sometimes measure "nearness" or "farness" in terms of the
Building Business Intelligence Using SAS: Content Development Examples by Tricia Aanderud and Angela Hall just published this month. This highly anticipated book—called “a must read for anyone using SAS® BI”* —is a quick-start guide that will help users move quickly from using only one of the SAS BI Clients to
History is easy to explain. We can always come up with some story for why this or that occurred. And, if the story sounds plausible enough, the explanation will be accepted as true. But can we ever know that the explanation is correct? How would we ever test it? If we
How we love shortcuts. Our life seems more efficient with them. I try to take the earlier train for a good parking spot that lets me exit early. Actually change that to any spot (my train station has tons of commuters with FEW parking spaces so getting up early is the
Way back when I learned to program, I remember a computer instructor explaining that an IF-THEN statement can be a relatively slow operation. He said "If a multiplication takes one unit of time, an IF statement requires about 70 units." I don't know where his numbers came from, or even
I have a love-hate relationship with spreadsheet data. I am interested in finding data to analyze, and if it arrives in the form of a spreadsheet, I'll take it. And I like to deliver results and reports, but often my constituents ask for it as a spreadsheet that they can
As SAS user Marje Fecht said "We all want a 'SAS programming assistant' to help us complete our jobs more quickly." Fecht, Senior Partner at Prowerk Consulting, then went on to say "In her book SAS Macro Programming Made Easy, Second Edition, Michele Burlew encourages us to take advantage of the SAS
The American Association of State Highway Transportation Officials recently released a top 10 list of transportation issues that will be “talked, written or tweeted and legislated about” in 2012. As expected, funding constraints and Congressional action on reauthorization appear on the list but the group also notes that natural disaster
Unlike prior versions of SAS OLAP technology, 9.2 provides more options for maintaining and refreshing OLAP cubes. With this comes some discussion about what each one does alone, and how pairing these techniques really provides SAS OLAP Server Administrators and cube developers a cornucopia of OLAP options. PROC OLAPOPERATE Remember
A variance-covariance matrix expresses linear relationships between variables. Given the covariances between variables, did you know that you can write down an invertible linear transformation that "uncorrelates" the variables? Conversely, you can transform a set of uncorrelated variables into variables with given covariances. The transformation that works this magic is
Some ideas sound great (combining chocolate with peanut butter) and turn out great (Reese's Peanut Butter Cup). Some ideas sound great (getting a face lift) but turn out bad (Kenny Rogers, Greta Van Susteren). Some ideas sound bad (a Run-DMC / Aerosmith duet) but turn out great ("Walk This Way"). Some ideas sound bad (letting
Have you ever wanted to run a sample program from the SAS documentation or wanted to use a data set that appears in the SAS documentation? You can: all programs and data sets in the documentation are distributed with SAS, you just have to know where to look! Sample data
Have you noticed the annoying stock art they put on The BFD blog header? All I can think of is "If those idiots only used SAS Forecast Server, they wouldn't have to draw graphs all over their window panes just to do forecasting." It must really p.o. the housekeeping staff at that
My colleague, Steve Serrao, just published a blog post on the proliferation of varied law enforcement approaches and their related phraseologies. After reading, I concur – hence, this blog’s title. I am not a huge fan of the term “predictive policing”. While others may love it and live it, and
We call it the "metadata profile", but really it's like a telephone number that connects you to your SAS environment. Just as a telephone number has component parts (country code, area code, exchange), the metadata profile contains information that allow you to "dial in" to your SAS servers. This information
In two previous blog posts I worked through examples in the survey article, "Robust statistics for outlier detection," by Peter Rousseeuw and Mia Hubert. Robust estimates of location in a univariate setting are well-known, with the median statistic being the classical example. Robust estimates of scale are less well-known, with
The other day I encountered the following SAS DATA step for generating three normally distributed variables. Study it, and see if you can discover what is unnecessary (and misleading!) about this program: data points; drop i; do i=1 to 10; x=rannor(34343); y=rannor(12345); z=rannor(54321); output; end; run; The program creates the
Recently, I had a discussion with a user concerning the volume of imagemap data generated for an interactive, web-based visual contain a large number of graphs. The large amount of imagemap data was causing problems with the current version of their web browser. The graphs consisted of either bar charts
Ten years ago I spent some time in women's undergarments*, as Director of Forecasting at Sara Lee Intimate Apparel (now Hanesbrands). Sure, it sounds glamorous -- product posters on our office walls, quarterly runway shows of new products, and partying with the full-figured Playtex models (some of whom were fuller than I figured).
So many of us struggle with this mountain. In fact, 68.27% of us get within sight of reaching the summit (while 95.47% of us are at least on a perceivable slope). We run, walk, crawl and sometimes slide our way uphill (from one direction or the other) until we finally
In a previous blog post on robust estimation of location, I worked through some of the examples in the survey article, "Robust statistics for outlier detection," by Peter Rousseeuw and Mia Hubert. I showed that SAS/IML software and PROC UNIVARIATE both support the robust estimators of location that are mentioned
We’ve just published Chris Olsen’s Teaching Elementary Statistics with JMP, which offers the latest research on best practices and how JMP can facilitate teaching statistics. To mark the book’s publication, we asked Chris to tell us the top three things every elementary statistics student should know. Statistics is about numbers
Love can make a person do bad, dangerous, stupid, and irresponsible things. Love of country can make a politician stray from his wife. Love of Pepsi can make a pop musician lose his hair in a pyrotechnics-gone-bad commercial. Love of acting can make academy award winners accept starring roles in Ishtar. And for
Note: as this is a popular topic, I've added a few notes with minor updates, including a link to a popular how-to tutorial video. In case you missed it, the first maintenance release for SAS 9.3 was recently released. Because we're all friends here, you may call it "SAS 9.3M1"
I was on vacation when a family member sidled up to me. "Rick, you're a statistician..." he began. I knew I was in trouble. He proceeded to tell me the story of Joseph "Newsboy" Moriarty, a New Jersey mobster who rose to prominence and became known as the bookie who
The single most costly employee benefit for any organization is health insurance, and the price is going up. From 2003-2009, the costs per hour worked for employee health insurance increased from $1.03 to $2.00. These costs continue to increase from 5%-7% per year. The reality is that employee health insurance costs will continue
Many cities and counties are taking the lead of private industry and developing 311 call centers to consolidate incoming calls for service and information requests from citizens. The business advantages are clear: Citizens have one number to call for service and information rather than having to waste time searching for
All too often an unspeakable tragedy leads to a needed policy or operational change through a newly-realized criminal justice system gap. While we continually work to minimize existing gaps, the reality is that as law enforcement evolves, so does the crime and so do the criminals. In recognition of those
Statistical programmers often need mathematical constants such as π (3.14159...) and e (2.71828...). Programmers of numerical algorithms often need to know machine-specific constants such as the machine precision constant (2.22E-16 on my Windows PC) or the largest representable double-precision value (1.798E308 on my Windows PC). Some computer languages build these
