A Macintosh BASIC program for fitting linear additive models to data by weighted least squares methods, with automatic elimination of redundant parameters from the model.

Abstract

A BASIC program for fitting linear additive models to data with weighted or unweighted least squares methods and matrix procedures is described. Written and compiled to run on Macintosh II type machines (68020/68030/68040) with coprocessor (68881/68882), the program fits the model supplied by the user as an X or design matrix and provides the option of making the model's parameters orthogonal. Predicted values plus regression and residual terms are calculated. For the weighted fit, the significance of the residual term is evaluated and redundant parameters sequentially and automatically removed until a minimum adequate model is achieved. An appropriate design matrix allows weighted fitting of models for multiway analyses of variance (e.g. factorial, nested and split plot), simple or multiple linear or curvilinear regression, combinations of these in covariance analyses, and genetic analyses (including diallel cross analyses). Sums of squares for individual parameters and orthogonal comparisons can be calculated by the program.