An APL-System for Analysing Multivariate Data

Summary

This caper introduces an interactive computer system based on the generalized multivariate analysis of the variance model (GMANOVA). This approach provides comprehensive possibilities for processing multivariate data. Handling of missing data is an integrated part of the system and it is done by using the EM algorithm. Missing data analyses can be easily carried out by using this system. This system also contains flexible possibilities for diagnostic checking of the model. The problem of influential measurements is considered. The influence analysis envisaged also serves as a means for comparing the robustness of various models to missing measurements and to different study designs. In addition to the usual tests of hypotheses within the GMANOVA model, also the single curves and their residuals can be analysed. Comprehensive summaries over individual curves can be performed. Graphical options for looking at the data and the family of growth curves, for example, are available. These programs are written in APL. The users familiar with APL can easily carry out further calculations, prepare further programs and intervene any sequence computations, and check the results immediately.