The determinant of a matrix arises in many statistical computations, such as in estimating parameters that fit a distribution to multivariate data. For example, if you are using a log-likelihood function to fit a multivariate normal distribution, the formula for the log-likelihood involves the expression log(det(Σ)), where Σ is the […]
Phone number validation in SAS
In SAS it’s trivial to perform basic validation of a US phone number using a regular expression, and this SAS macro goes way behind the basic validation rules: it checks several rules, in service area codes, directory service, and special ……
Stored Process: Using Alternating Background Color with PROC REPORT
I remember when I began learning how to program using SAS. One of my first tasks was to create a set of reports that listed the trouble tickets from the customer. This was before it was easy to get information from SAS to Excel and the goal was to …
NOTE: Seasonal Cycles and Date Increments (once more unto the breach)
I’ve posted a couple of articles recently about the INTNX and INTCK functions for dealing with date/time/datetime manipulation. Whilst researching these I stumbled across some related functions that I’d not heard of before. These functions manipulate d…
Using source control management with SAS Enterprise Guide
I work on a variety of projects at SAS, most of which require some level of team collaboration in source management systems. Due to the many technologies that we work with, SAS developers use different source management tools for different purposes. I’ve got projects in CVS, Subversion, and Git. When […]
DNN Error
I have been using DotNetNuke (DNN) A LOT recently. For building a web framework, it absolutely rocks and is very easy to use. It is also very popular (I think 800k sites and growing) so there are loads of add-ons, videos, help guides, etc. Plus, it is …