FORTRAN Subprograms Research Articles

Programs to Compute Distribution Functions and Critical Values for Extreme Value Ratios for Outlier Detection

A set of FORTRAN subprograms is presented to compute density and cumulative distribution functions and critical values for the range ratio statistics of Dixon (1951, The Annals of Mathematical Statistics ) These statistics are useful for detection of outliers in small samples.

New type signatures for legacy Fortran subroutines

We are currently developing a methodological framework for reverse engineering Fortran77 programs used by Electricité de France, in which the first step is the construction of an algebraic specification which faithfully represents the Fortran code. To construct this specification, we must decide on a coherent set of "profiles" (type signatures) for the specifications of the Fortran sub-programs. We propose an analysis of the dynamic aliases between formal and actual sub-program arguments in order to derive these profiles. In many examples of real Fortran code this analysis does not give satisfactory results if arrays are treated as indivisible. Instead, we must take into account which fragment of the array may really be accessed by the sub-program. We have therefore implemented our analysis as an extension of the PIPS code parallelisation tool, which provides us with a precise analysis of inter-procedural array data-flow.

Automatic Rendering of Astrodynamics Expressions for Efficient Evaluation

In this paper, we describe the automatic rendering of expressions computed using symbolic manipulation. Computations from astrodynamics frequently can be put in a fixed hierarchy of polynomials and Fourier series. Once in this form, FORTRAN subprograms can be generated automatically in a form that lends itself to numerical evaluation. The goal of the current work is to present an approach for using symbolic manipulation techniques to produce a Fortran representation of the normalized Hamiltonian and other supporting equations representing as many of the actual physical effects on satellites as possible.

Application of mixed language programming

Mixed language programming is one way to combine the best facilities of various programming languages and to make use of investments in existing code. It has received great attention in recent years. This is due to the successful acceptance of some high-level languages and to the strong survival of the classical languages. This paper stresses the importance of mixed language programming, discusses some of the associated problems, and gives a structured view on the various ways to realize mixed language programming. Several examples are given on using Fortran subprograms from programs written in Ada, C and Pascal.

Mudpack: Multigrid portable fortran software for the efficient solution of linear elliptic partial differential equations

mudpack is a package of portable fortran subprograms which use multigrid iteration for solving real or complex elliptic partial differential equations. The solution regions are rectangles in two dimensions and boxes in three dimensions. Any combination of periodic, Dirichlet, and mixed-derivative boundary conditions is allowed. The equations are automatically discretized using second-order finite differencing. The package will vectorize on Cray computers. Examples are given which demonstrate ease of use, efficiency, and applicability to a wide range of problems.

A global optimization algorithm using stochastic differential equations

SIGMA is a set of FORTRAN subprograms for solving the global optimization problem, which implements a method founded on the numerical solution of a Cauchy problem for a stochastic differential equation inspired by statistical mechanics. This paper gives a detailed description of the method as implemented in SIGMA and reports the results obtained by SIGMA attacking, on two different computers, a set of 37 test problems which were proposed elsewhere by the present authors to test global optimization software. The main conclusion is that SIGMA performs very well, solving 35 of the problems, including some very hard ones. Unfortunately, the limited results available to us at present do not appear sufficient to enable a conclusive comparison with other global optimization methods.

GAP

The GAP package has been developed to permit the linking of standard GPSS models to a series of FORTRAN subprograms. Since the GAP subprograms are transparent to the user, knowledge of the FORTRAN language is not needed. GAP provides an easy mechanism to obtain, among other things, values from a number of standard statistical distributions, permits the loading of MSAVEVALUEs and other SNAs using data cards and provides statistical analysis of the GPSS model output.

A simply constructable user-oriented computer language using fortran

One important task of the industrial engineer is to be an interface person—between operations and planning, between workers and their physical environment, between bench level tasks and systems level management, and with growing need, between the computer and the user. The latter has been caused in part by the programming requirement to express how a task is to be done, rather than what is to be done. The IEs role here is to provide the interface to ask the “what” questions. This paper addresses one strategy for constructing the computer-user interface. Using a core set of sixteen short FORTRAN subprograms, a simple procedure for constructing user oriented conversational computer languages has been developed (seven subprograms are directed at the conversational language and nine are list handling routines). This core set has been used successfully to develop user packages for medical doctors doing cell kinetics simulation in cancer research, for energy policy makers to access and manipulate time series energy data, for undergraduates to solve statistical and mathematical programming problems. The procedure is machine independent, only requiring a FORTRAN compiler, and can be used by the IE to bridge the gap between the user with a question, and the solution power of the computer.

Certification of “Algorithm 541: Efficient Fortran Subprograms for the Solution of Separable Elliptic Partial Differential Equations [D3

Certification of “Algorithm 541: Efficient Fortran Subprograms for the Solution of Separable Elliptic Partial Differential Equations [D3

Algorithm 541: Efficient Fortran Subprograms for the Solution of Separable Elliptic Partial Differential Equations [D3

Algorithm 541: Efficient Fortran Subprograms for the Solution of Separable Elliptic Partial Differential Equations [D3

Compartmental analysis—I: LINDE, a program using an analytical method of integration with constituent matrices

A new package of programs LINDE has been developed to handle classical compartmental problems as well as new specifications (time-independent control) in that field, giving access to many structured methods of use. Since the predetermined functions are to be FORTRAN sub-programs, they can freely be written by the user. The new ideas and algorithms are widely described from a theoretical point of view: construction of “constituent matrices” to solve the basical differential equation, conditions of existence and uniqueness of a solution to a “problem of predetermination”, definition of a new parameter, the “latency time”, which can help to avoid unrealistic solutions to a problem of control.

PORT

PORT is a structured library of Fortran subprograms for numerical computation. The library has been under development at Bell Laboratories for three years and is now in its second edition. One of the most important aspects of the project has been the emphasis on the portability of the library. This note outlines the techniques used to make the library portable, and also discusses the error handling and scratch storage allocation in the library. The report concludes with an overview of the structure and contents of the library.

Package for Calculating with B-Splines

Eight FORTRAN subprograms for dealing computationally with piecewise polynomial functions (of one variable) are presented. The package is built around an algorithm for the stable evaluation of B-splines of arbitrary order and with knots of arbitrary multiplicity. Four examples illustrate how one might use these routines: interpolation by splines of general order k (and not necessarily at the knots); least squares approximation by splines to discrete data; the determination of the derivative of a spline with respect to a knot; and the approximate solution of an ordinary differential equation with rather general side conditions by collocation.

Efficient FORTRAN subprograms for the solution of elliptic partial differential equations (abstract)

The purpose of this paper is to describe technical note, NCAR TN/IA-109, which is intended to provide scientists with a package of computer programs which make use of current methods for solving elliptic partial differential equations. Computer models of geophysical processes often require the numerical solution of elliptic partial differential equations. This is particularly true for models which make use of stream functions, velocity potentials, or vorticity equations, or in which the pressure of an incompressible fluid is computed. The numerical solution of elliptic equations can be a formidable programming task. Also, the equations are often time-dependent, requiring repeated solutions and, hence, considerable computing resources. Efficient, reliable, and well-documented computer subroutines for solving such equations are needed. With recent advances in computing methods, it became apparent to the authors that a very large class of elliptic equations (separable) could be solved rapidly and with minimal storage. Of particular importance was the fact that, as a result of work on singular problems, this class was free of special cases for which solutions could not be obtained numerically.

Experimental and theoretical studies of a thyristor controlled two-phase motor

The performance of two-phase induction motor with the phase voltages controlled by symmetrically triggered, back-to-back thyristor pairs in series with the stator windings is investigated. Results obtained from experiments carried out on a 1 horsepower wound-rotor test machine are compared with results obtained by a simulation study using a cross-field model for the motor. The CSMP analogdigital simulation technique is found particularly suited to this type of problem since the logic statements required to describe the behaviour of the thyristors are easily included in FORTRAN subprograms. It is demonstrated that the computed results predict, to the accuracy expected of a constant parameter motor model, the first-order performance of the actual system. Cas Verhalten eines Zweiphasen Inductionsmotors wird untersucht, in dem die Phasenspannungen durch symmetrische antiparallel Paare von Thyristoren geregelt werden die in Serie mit den Statorwicklungen geschaltet sind. Resultate der Experimente min einer 1 PS Testmachine mit gewickeltem Rotor werden rerglichen mit Ergebnissen einer Simulation studie, die ein Querfeld modell fur den Motor benutzt. Diese analog-digitale Simulationstechnik ist für diese Art von Problemen besonders geeignet, da die logischen Anweisungen, die für die Beschreibung des Verhaltens der Thyristoren benötigt werden, leicht in FORTRAN-Unterprogramme aufgenommen werden können. Es wird gezeigt, dass die berechneten Ergebnisse das Verhalten des wirklicken Systems in erster Ordnung mi t der von einem Modell mit konstanten Parametern zu erwartenden Genauigkeit voraussagen.

A mixed language system POP‐2 and FORTRAN

AbstractIn designing a POP‐2 compiler for the CDC 6000 series machines, it became apparent that there was a requirement to link to precomiled FORTRAN subprograms in order to use the advantages of FORTRAN and to make use of the extensive liberaries available. This paper describes the design considerations, the principal problems involved and the subsequent implementation of the POP‐2/FORTRAN system. It is concluded that the general design aims were successfully achieved, that is: the system is primarily a POP‐2 system, calls to FORTRAN subprograms have exactly the same syntax as calls to POP‐2 functions and the restrictions on FORTRAN subprograms are minimal. The space overhead of having FORTRAN unused is about 10 per cent.