GLIM4 — Developments in Model Fitting

GLIM was first developed with the simple aim of providing a software tool that would allow the fitting of Generalised Linear Models, with a small number of utilities necessary for practical data analysis. Today, using GLIM377 (Payne et al, 1985) the variety of models that GLIM has been used to fit (Aitkin et al, 1989) is far wider than anyone could have imagined in the early days of release 1. For the new release, the temptation to extend the fitting procedure of GLIM to include models well outside those of GLMs has been resisted. Rather, it is the intention of the current enhancement to incorporate some of the facilities that will extend the range of GLMs and their extensions which can be fitted; most effort has been concentrated on extending the model formula syntax, to allow the user greater control and access to system structures, to improve the operation and readability of GLIM macros and to provide simple high-quality graphics to allow graphical techniques for model checking and display to be used.