ELLPACK 77 Contributor's Guide

This report gives the information needed for contributors to the ELLPACK cooperative effort to develop and evaluate methods and software for elliptic partial differential equations. The overall structure is described and then detailed information is given about the modules and their interfaces. The information is intended to be sufficient to allow the reader to prepare modules for contribution to ELLPACK 77, the version of ELLPACK with rectangular geometry. The user interface is described in some detail as certain features affect the way modules should be written. The portability notes are only reminders of the principal points one has to keep in mind while writing code that is intended to be run on a variety of machines. This is an updated and specialized version of ELLPACK Contributor's Guide, CSD-208, revised September 16, 1977. Other relevant documents are the ELLPACK U~erls ~uide, CSD-TR 226 and the ELLPACK Distribution Guide, CSD-TR 254. ELLPACK 77 CONTRIBUTOR'S GUIDE 1. ELLPACK STRUCTURE. The basic organization of ELLPACK is illustrated by the diagram in Figure 1. ELLPACK PREPROCESSOR