Transportable package software

Abstract

AbstractPackage programs allow people who are not computer experts to use the power of machine computation for specialized purposes. Because the designers of scientific packages are more often experts in their scientific field than in computing, they may ignore issues of transportability and ease‐of‐use until too late, and produce a package that is difficult to use, and difficult to move to a different computer. In this paper we suggest some techniques to aid the scientific package designer.We suggest a kernel of routines that interface to the peculiar operating system of each machine, providing sophisticated but standard operating system services. This kernel makes the operating system of each computer appear identical and does not pose a difficult implementation problem. Above this interface all code can be machine‐independent, without sacrificing power and ease of use on any machine.We also suggest some novel organizations of processing routines designed to make the system easy to alter and extend. Complete independence of modules encourages centralization of tasks, which is both efficient and essential for easy extension. With this organization, the vast preponderance of package code can be written in machine‐independent ANSI FORTRAN. We suggest the use of a preprocessor like RATFOR to make this more pleasant.The paper closes with an application to an image‐processing package, in which a major problem is the flexible sequencing of processing routines.