The DO Loop
Statistical programming in SAS with an emphasis on SAS/IML programs
A previous article discusses a "Catch-22" paradox for fitting nonlinear regression models: You can't estimate the parameters until you fit the model, but you can't fit the model until you provide an initial guess for the parameters! If your initial guess for the parameters is not good enough, the nonlinear
I have previously written about the moment-ratio diagram as a graphical tool for modeling univariate distributions and also as a tool for examining the distribution of the skewness and kurtosis statistics for distributions. The simple moment-ratio (M-R) diagram from my book (Wicklin, 2013, Simulating Data with SAS, Chapter 16) is
This article shows how to classify a set of high-dimensional data into orthants. An orthant is the d-dimensional generalization of a quadrant. For 2-D Euclidean space, there are four quadrants, often labeled by Roman numerals I-IV. The quadrants are open sets that are defined by the signs of each coordinate
This article shows how to use SAS to implement the ISO algorithm to generate (and validate) a Universal Loan Identifier (ULI). A ULI is a long string of numbers and letters that serves as a unique identifier that is used for certain financial transactions. The ISO standard ensures that banks
On social media, a SAS user reported that SAS could not compute the modulo of an extremely large integer. In SAS, the modulo operation is usually performed by using the MOD function, which computes the remainder of dividing an integer, N, by another integer, d. (In symbols, the remainder is
A previous article discusses the Gini-Simpson diversity index and how to compute it in SAS. Suppose you have a sample that contains R classes. (Classes are also called groups or categories.) Intuitively, the sample exhibits "high diversity" if the class sizes are approximately equal. The sample shows "low diversity" if