Chapter 9 - Program Architecture

Abstract

This chapter describes the general functionality of each aspect of the code. The input module has two basic functions. The first is to perform the full input processing, and the second is to recognize and perform a restart function that will not require the full input processing. Full input processing is required at the beginning of a new simulation, and in this instance, the input processor will read and construct all of the data arrays to be stored in memory for the entire spatial and temporal domain of the problem. A skilled programmer will build in many input consistency checks to ensure that the processing of these very large inputs is internally correct and does not contain inherent errors. Unlike the input and analysis modules, in which one can draw a process flow diagram of the program logic flow, the output module is more like a parking garage (or collection) of all of the subroutines that generate input output. Generally, these subroutines can and often are called by either the input module or the analysis module, and keeping them all in one location is simply a convenient way to manage the Fortran source.