Welcome to Statistics and Operations Research

SAS has long developed software for data analysis, econometrics, operations research, and quality improvement. The purpose of these pages is to provide our users with technical information about using this software, including details about software capabilities, examples, papers, e-newsletter, and communities.

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Customizing the Kaplan-Meier Survival Plot

You might not know that the SAS/STAT documentation includes an entire chapter on how to customize the Kaplan-Meier plot. This plot, which displays survival (time-to-event) data, is probably one of the most popular statistical plots in play. Learn how to customize it using ODS Graphics so that it displays exactly what you want and how you want to do it. For more information about this documentation, see Distinguished Research Statistician Developer Warren Kuhfeld's blog post.

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Check out the our newest videos.

The HPGENSELECT Procedure: Model Selection for Generalized Linear Models and More

Estimating Causal Effects from Observational Data with PROC CAUSALTRT

Introducing the PSMATCH Procedure for Propensity Score Analysis

Multivariate Time Series Analysis with the VARMAX Procedure

Telling the Story of Your Process with Graphical Enhancements of Control Charts

Blog Using the FASTQUAD Suboption in PROC GLIMMIX

One of the most expensive pieces of estimating a generalized linear mixed model is evaluating the likelihood function. There are six different methods for taking on this calculation in PROC GLIMMIX, from pseudo-likelihood evaluation to estimating the exact likelihood. When choosing from these methods, you need to consider the effects of estimation bias with certain response types. You also need to weigh the cost of the likelihood evaluation. Some of these methods require more memory and run time than others. Beginning with SAS/STAT 14.1 in SAS 9.4 TS11M3, the FASTQUAD quad-option for the METHOD=QUAD option can often alleviate long run times and memory constraints. FASTQUAD uses the multilevel adaptive quadrature algorithm proposed by Pinheiro and Chao (2006).

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Writing Packages: A New Way to Distribute and Use SAS/IML Programs

This paper describes how SAS/IML programmers can construct, upload, download, and install packages. SAS/IML 14.1 enables you to author, install, and call packages. A package consists of SAS/IML source code, documentation, data sets, and sample programs.

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