SAS provides procedures to fit common probability distributions to sample data. You can use PROC UNIVARIATE in Base SAS or PROC SEVERITY in SAS/ETS software to estimate the distribution parameters for approximately 20 common distributions, including normal, lognormal, beta, gamma, and Weibull. Since there are infinitely many distributions, you may eventually need to fit a distribution that SAS does not natively support. There are three often-used methods for fitting the parameters of a distri...| The DO Loop
Many common probability distributions contain terms that increase or decrease quickly, such as the exponential function and factorials. The numerical evaluation of these quantities can result in numerical overflow (or underflow). This is why we often work on the logarithmic scale: on the log-scale, the numerical computations for equations such as the log-likelihood function are more stable. This article demonstrates a different trick that is useful for computing a sum of exponential terms. I ...| The DO Loop
Suppose you measure data weekly.| The DO Loop
Dating can be a challenge. No, I'm not talking about the process of finding a soulmate. I'm talking about managing days, weeks, months, and years in statistical analyses and reports! One challenge is how to number the weeks of the year. Because there are seven days in a week, 52 weeks equals 7*52 = 364 days of the year. Of course, there are 365 (or 366) days in a year, so the "first week of the year" does not always start on New Year's Day. But when does it start? What date is the first day o...| The DO Loop
I follow several data visualization experts on social media.| The DO Loop