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NASA NTRS1986

Automated FORTRAN conversion

The most pratical solution to the conversion of FORTRAN to other programming languages which STO and a few others have adopted, uses an intermediate language that is easy to translate FORTRAN into, and allows for source codes in other languages to be generated automatically. The intermediate language is the union of all other programming languages (and the trick is to create a useful union) with some extensions that reflect the nature of the algorithms. The benefits of this approach are many. First the original FORTRAN program has to be rewritten only once, and then only parts of the program: most FORTRAN code passes through without and change (i.e., assignment and simple IF statements). Software tools are provided to ease this initial translation. Once in the intermediate language, the algorithm can then be obtained in any other language automatically. An example of a subroutine from the Rispack library in ten different languages is given.

Aharonian, Gregory↗

NASA NTRS2000

Developing CORBA-Based Distributed Scientific Applications From Legacy Fortran Programs

An efficient methodology is presented for integrating legacy applications written in Fortran into a distributed object framework. Issues and strategies regarding the conversion and decomposition of Fortran codes into Common Object Request Broker Architecture (CORBA) objects are discussed. Fortran codes are modified as little as possible as they are decomposed into modules and wrapped as objects. A new conversion tool takes the Fortran application as input and generates the C/C++ header file and Interface Definition Language (IDL) file. In addition, the performance of the client server computing is evaluated.

Sang, Janche↗

NASA NTRS2003

Aviation Safety Modeling and Simulation (ASMM) Propulsion Fleet Modeling: A Tool for Semi-Automatic Construction of CORBA-based Applications from Legacy Fortran Programs

Within NASA's Aviation Safety Program, NASA GRC participates in the Modeling and Simulation Project called ASMM. NASA GRC s focus is to characterize the propulsion systems performance from a fleet management and maintenance perspective by modeling and through simulation predict the characteristics of two classes of commercial engines (CFM56 and GE90). In prior years, the High Performance Computing and Communication (HPCC) program funded, NASA Glenn in developing a large scale, detailed simulations for the analysis and design of aircraft engines called the Numerical Propulsion System Simulation (NPSS). Three major aspects of this modeling included the integration of different engine components, coupling of multiple disciplines, and engine component zooming at appropriate level fidelity, require relatively tight coupling of different analysis codes. Most of these codes in aerodynamics and solid mechanics are written in Fortran. Refitting these legacy Fortran codes with distributed objects can increase these codes reusability. Aviation Safety s modeling and simulation use in characterizing fleet management has similar needs. The modeling and simulation of these propulsion systems use existing Fortran and C codes that are instrumental in determining the performance of the fleet. The research centers on building a CORBA-based development environment for programmers to easily wrap and couple legacy Fortran codes. This environment consists of a C++ wrapper library to hide the details of CORBA and an efficient remote variable scheme to facilitate data exchange between the client and the server model. Additionally, a Web Service model should also be constructed for evaluation of this technology s use over the next two- three years.

Sang, Janche↗

NASA NTRS1997

High Performance Object-Oriented Scientific Programming in Fortran 90

We illustrate how Fortran 90 supports object-oriented concepts by example of plasma particle computations on the IBM SP. Our experience shows that Fortran 90 and object-oriented methodology give high performance while providing a bridge from Fortran 77 legacy codes to modern programming principles. All of our object-oriented Fortran 90 codes execute more quickly thatn the equeivalent C++ versions, yet the abstraction modelling capabilities used for scentific programming are comparably powereful.

Scientific Programming↗

NASA NTRS2006

FORTRAN Versions of Reformulated HFGMC Codes

Several FORTRAN codes have been written to implement the reformulated version of the high-fidelity generalized method of cells (HFGMC). Various aspects of the HFGMC and its predecessors were described in several prior NASA Tech Briefs articles, the most recent being HFGMC Enhancement of MAC/GMC (LEW-17818-1), NASA Tech Briefs, Vol. 30, No. 3 (March 2006), page 34. The HFGMC is a mathematical model of micromechanics for simulating stress and strain responses of fiber/matrix and other composite materials. The HFGMC overcomes a major limitation of a prior version of the GMC by accounting for coupling of shear and normal stresses and thereby affords greater accuracy, albeit at a large computational cost. In the reformulation of the HFGMC, the issue of computational efficiency was addressed: as a result, codes that implement the reformulated HFGMC complete their calculations about 10 times as fast as do those that implement the HFGMC. The present FORTRAN implementations of the reformulated HFGMC were written to satisfy a need for compatibility with other FORTRAN programs used to analyze structures and composite materials. The FORTRAN implementations also afford capabilities, beyond those of the basic HFGMC, for modeling inelasticity, fiber/matrix debonding, and coupled thermal, mechanical, piezo, and electromagnetic effects.

Arnold, Steven M.↗

NASA NTRS1972

FGRAAL: FORTRAN extended graph algorithmic language

The FORTRAN version FGRAAL of the graph algorithmic language GRAAL as it has been implemented for the Univac 1108 is described. FBRAAL is an extension of FORTRAN 5 and is intended for describing and implementing graph algorithms of the type primarily arising in applications. The formal description contained in this report represents a supplement to the FORTRAN 5 manual for the Univac 1108 (UP-4060), that is, only the new features of the language are described. Several typical graph algorithms, written in FGRAAL, are included to illustrate various features of the language and to show its applicability.

Basili, V. R.↗

NASA NTRS1972

A brief description and comparison of programming languages FORTRAN, ALGOL, COBOL, PL/1, and LISP 1.5 from a critical standpoint

Several common higher level program languages are described. FORTRAN, ALGOL, COBOL, PL/1, and LISP 1.5 are summarized and compared. FORTRAN is the most widely used scientific programming language. ALGOL is a more powerful language for scientific programming. COBOL is used for most commercial programming applications. LISP 1.5 is primarily a list-processing language. PL/1 attempts to combine the desirable features of FORTRAN, ALGOL, and COBOL into a single language.

Mathur, F. P.↗

NASA NTRS1971

Optimization techniques for FORTRAN 4 (G and H) programs written for the IBM 360 under OS

A fairly complete list is reported of programming techniques which are available to the programmer for optimizing the execution time of production programs written in FORTRAN IV (G and H) for the IBM 360 under OS. After the program has been complied under FORTRAN H, OPT=2, then the process of actually changing code begins. The bulk of execution time of FORTRAN programs can almost always be attributed to a few loops, and primary consideration is given to these.

Dean, J. L.↗

NASA NTRS1975

FORTRAN Automated Code Evaluation System (FACES) user's manual, version 2

A system which provides analysis services for FORTRAN based software systems not normally available from system software is presented. The system is not a compiler, and compiler syntax diagnostics are not duplicated. For maximum adaptation to FORTRAN dialects, the code presented to the system is assumed to be compiler acceptable. The system concentrates on acceptable FORTRAN code features which are likely to produce undesirable results and identifies potential trouble areas before they become execution time malfunctions.

Source record↗

NASA NTRS1980

Structured FORTRAN preprocessor

Structured-programming features simplify software design. Programmer needs only few control statements to code program in format easy to debug and maintain, freeing him/her from flow constraints of standard FORTRAN. Program is written in ANSI FORTRAN and is compatible with machine supporting FORTRAN compiler that accepts ANSI statements. It has been implemented on IBM 370.

Austin, S.↗

NASA NTRS1982

An Automated FORTRAN documenter

A set of programs designed to help R&D programmers document their FORTRAN programs more effectively were written. The central program reads FORTRAN source code and asks the programmer questions about things it has not heard of before. It inserts the answers to these questions as comments into the FORTRAN code. The comments, as well as extensive cross-reference information, are also written to an unformatted file. Other programs read this file to produce printed information or to act as an interactive document.

Erickson, T.↗

NASA NTRS1983

CDC to CRAY FORTRAN conversion manual

Documentation describing software differences between two general purpose computers for scientific applications is presented. Descriptions of the use of the FORTRAN and FORTRAN 77 high level programming language on a CDC 7600 under SCOPE and a CRAY XMP under COS are offered. Itemized differences of the FORTRAN language sets of the two machines are also included. The material is accompanied by numerous examples of preferred programming techniques for the two machines.

Mcgary, C.↗

NASA NTRS1988

Mapper of FORTRAN Programs

SUPERMAP computer program designed to produce map of all components and attributes of FORTRAN program. Maps usage of all variables and all COMMONs used in FORTRAN program. Maps alignment of subprograms CALLed with the arguments and dummy arguments of the CALLed subprogram. Tallies externals called by each module. Written in FORTRAN 77.

Guest, Clayton J.↗

NASA NTRS1988

NESSUS (Numerical Evaluation of Stochastic Structures Under Stress)/EXPERT: Bridging the gap between artificial intelligence and FORTRAN

The development of a probabilistic structural analysis methodology (PSAM) is described. In the near-term, the methodology will be applied to designing critical components of the next generation space shuttle main engine. In the long-term, PSAM will be applied very broadly, providing designers with a new technology for more effective design of structures whose character and performance are significantly affected by random variables. The software under development to implement the ideas developed in PSAM resembles, in many ways, conventional deterministic structural analysis code. However, several additional capabilities regarding the probabilistic analysis makes the input data requirements and the resulting output even more complex. As a result, an intelligent front- and back-end to the code is being developed to assist the design engineer in providing the input data in a correct and appropriate manner. The type of knowledge that this entails is, in general, heuristically-based, allowing the fairly well-understood technology of production rules to apply with little difficulty. However, the PSAM code, called NESSUS, is written in FORTRAN-77 and runs on a DEC VAX. Thus, the associated expert system, called NESSUS/EXPERT, must run on a DEC VAX as well, and integrate effectively and efficiently with the existing FORTRAN code. This paper discusses the process undergone to select a suitable tool, identify an appropriate division between the functions that should be performed in FORTRAN and those that should be performed by production rules, and how integration of the conventional and AI technologies was achieved.

Fink, Pamela K.↗

NASA NTRS1991

Library Of Subprograms In FORTRAN 77

MATH77, Release 3.17, is library of 412 FORTRAN 77 subprograms for use in numerical computation. Subprograms providing machine and system characteristic parameters make library operational on any computer system supporting full FORTRAN 77 standard. Portability and high quality of subprograms and user's manual make MATH77 extremely versatile and valuable tool for all numerical computation applications. Written in FORTRAN 77. Program and documentation copyrighted products of California Institute of Technology.

Lawson, Charles L.↗

NASA NTRS1993

High performance FORTRAN without templates: An alternative model for distribution and alignment

Language extensions of FORTRAN are being developed which permit the user to map data structures to the individual processors of distributed memory machines. These languages allow a programming style in which global data references are used. Current efforts are focussed on designing a common basis for such languages, the result of which is known as High Performance Fortran (HPF). One of the central debates in the HPF effort revolves around the concept of templates, introduced as an abstract index space to which data could be aligned. A model for the mapping of data which provides the functionality of High Performance Fortran distributions without the use of templates is presented.

Chapman, Barbara↗

NASA NTRS1992

An object-oriented data reduction system in Fortran

A data reduction system for the AAO two-degree field project is being developed using an object-oriented approach. Rather than use an object-oriented language (such as C++) the system is written in Fortran and makes extensive use of existing subroutine libraries provided by the UK Starlink project. Objects are created using the extensible N-dimensional Data Format (NDF) which itself is based on the Hierarchical Data System (HDS). The software consists of a class library, with each class corresponding to a Fortran subroutine with a standard calling sequence. The methods of the classes provide operations on NDF objects at a similar level of functionality to the applications of conventional data reduction systems. However, because they are provided as callable subroutines, they can be used as building blocks for more specialist applications. The class library is not dependent on a particular software environment thought it can be used effectively in ADAM applications. It can also be used from standalone Fortran programs. It is intended to develop a graphical user interface for use with the class library to form the 2dF data reduction system.

Bailey, J.↗

NASA NTRS1993

Dynamic data distributions in Vienna Fortran

Vienna Fortran is a machine-independent language extension of Fortran, which is based upon the Single-Program-Multiple-Data (SPMD) paradigm and allows the user to write programs for distributed-memory systems using global addresses. The language features focus mainly on the issue of distributing data across virtual processor structures. Those features of Vienna Fortran that allow the data distributions of arrays to change dynamically, depending on runtime conditions are discussed. The relevant language features are discussed, their implementation is outlined, and how they may be used in applications is described.

Chapman, Barbara↗