Showing papers on "Fortran published in 1981"

Optimum Path Planning for Mechanical Manipulators

Abstract: To assure a successful completion of an assigned task without interruption, such as the collision with fixtures, the hand of a mechanical manipulator often travels along a preplanned path. An advantage of requiring the path to be composed of straight-line segments in Cartesian coordinates is to provide a capability for controlled interaction with objects on a moving conveyor. This paper presents a method of obtaining a time schedule of velocities and accelerations along the path that the manipulator may adopt to obtain a minimum traveling time, under the constraints of composite Cartesian limit on linear and angular velocities and accelerations. Because of the involvement of a linear performance index and a large number of nonlinear inequality constraints, which are generated from physical limitations, the “method of approximate programming (MAP)” is applied. Depending on the initial choice of a feasible solution, the iterated feasible solution, however, does not converge to the optimum feasible point, but is often entrapped at some other point of the boundary of the constraint set. To overcome the obstacle, MAP is modified so that the feasible solution of each of the iterated linear programming problems is shifted to the boundaries corresponding to the original, linear inequality constraints. To reduce the computing time, a “direct approximate programming algorithm (DAPA)” is developed, implemented and shown to converge to optimum feasible solution for the path planning problem. Programs in FORTRAN language have been written for both the modified MAP and DAPA, and are illustrated by a numerical example for the purpose of comparison.

PAN AIR: A Computer Program for Predicting Subsonic or Supersonic Linear Potential Flows About Arbitrary Configurations Using a Higher Order Panel Method. Volume 1; Theory Document (Version 1.1)

Abstract: The Maintenance Document Version 3.0 is a guide to the PAN AIR software system, a system which computes the subsonic or supersonic linear potential flow about a body of nearly arbitrary shape, using a higher order panel method. The document describes the overall system and each program module of the system. Sufficient detail is given for program maintenance, updating, and modification. It is assumed that the reader is familiar with programming and CRAY computer systems. The PAN AIR system was written in FORTRAN 4 language except for a few CAL language subroutines which exist in the PAN AIR library. Structured programming techniques were used to provide code documentation and maintainability. The operating systems accommodated are COS 1.11, COS 1.12, COS 1.13, and COS 1.14 on the CRAY 1S, 1M, and X-MP computing systems. The system is comprised of a data base management system, a program library, an execution control module, and nine separate FORTRAN technical modules. Each module calculates part of the posed PAN AIR problem. The data base manager is used to communicate between modules and within modules. The technical modules must be run in a prescribed fashion for each PAN AIR problem. In order to ease the problem of supplying the many JCL cards required to execute the modules, a set of CRAY procedures (PAPROCS) was created to automatically supply most of the JCL cards. Most of this document has not changed for Version 3.0. It now, however, strictly applies only to PAN AIR version 3.0. The major changes are: (1) additional sections covering the new FDP module (which calculates streamlines and offbody points); (2) a complete rewrite of the section on the MAG module; and (3) strict applicability to CRAY computing systems.

Efficient fortran subprograms for the solution of elliptic partial differential equations

Abstract: Publisher Summary This chapter discusses the efficient FORTRAN subprograms for the solution of elliptic partial differential equations. FISHPAK is a package of FORTRAN subroutines that has been developed at the National Center for Atmospheric Research. The package provides a basic capability to automatically produce finite difference approximations to Helmholtz's equation defined on a rectangle in a particular co-ordinate system. Also, there are routines for the more general separable elliptic equation and three-dimensional Helmholtz equation in Cartesian coordinates. The package is comprised of a set of drivers, a set of solvers, and an extensive subpackage for computing Fourier transforms. Drivers are available on two different types of finite difference grids, namely, centered, and staggered. In a centered grid, the physical boundaries coincide with the grid lines, whereas in a staggered grid, the physical boundaries are located at one-half grid spacing away from the grid lines. All drivers use a uniform or equally spaced grids in the given coordinate system.

Algorithm 566: FORTRAN Subroutines for Testing Unconstrained Optimization Software [C5], [E4]

Abstract: A partial listing of the FORTRAN package of subroutines for testing unconstrained optimazation software is given with a brief description of the subroutines. The following three problem areas are considered: (1) zeros of systems of N nonlinear functions in N variables; (2) least square minimization of M nonlinear functions in N variables; (3) unconstrained minimization of an objective function with N variables. To test a code in any of the three problem areas, the user must provide a driver and interface routine. The package includes example drivers and interface routines for each of the problem areas. Sample data are also provided. (SC)

DATAPLOT—an interactive high-level language for graphics, non-linear fitting, data analysis, and mathematics

Abstract: This paper describes the design philosphy and features of DATAPLOT—a high-level (free-format English-like syntax) language for:1) graphics (continuous or discrete);2) fitting (linear or non-linear);3) general data analysis;4) mathematics.DATAPLOT was developed originally in 1977 in response to data analysis problems encountered at the National Bureau of Standards. It has subsequently been the most heavily-used interactive graphics and non-linear fitting language at NBS. It is a valuable tool not only for “raw” graphics, but also for manuscript preparation, modeling, data analysis, data summarization, and mathematical analysis. DATAPLOT may be run either in batch mode or interactively, although it was primarily designed for (and is most effectively used in) an interactive environmnet. DATAPLOT graphics may appear on many different types of output devices. Due to its modular design and underlying ANSI FORTRAN (PFORT) code, DATAPLOT is portable to a wide variety of computers.The paper is divided into three general parts: part 1 deals with background motivation and design philosophy; part 2 deals with capability and implementation features; part 3 deals with a comparison of DATAPLOT to other systems/languages.

GRG2: an all FORTRAN general purpose nonlinear optimizer

Abstract: GRG2 solves nonlinear optimization problems in which the objective and constraint functions can have nonlinearities of any form but should be differentiable Both single and double precision versions are available for computers of all major vendors

Algorithm for the solution of the Bottleneck Assignment Problem

Abstract: The FORTRAN implementation of an efficient algorithm which solves the Bottleneck Assignment Problem is given. Computational results are presented, showing the proposed method to be generally superior to the best known algorithms.

Precompilation of Fortran Programs to Facilitate Array Processing

Abstract: The automatic recognition of array operations in Fortran programs can now be applied to attached array processors using vectorizing precompiler software.

The design and analysis of low-speed airfoils

Abstract: PROFILE program solves diverse and inverse airfoil-flow problems. It combines conformational mapping method for design of airfoils with prescribed velocity-distribution characteristics, panel method for potential-flow analysis, and boundary-layer method. PROFILE is written in FORTRAN IV for implementation on CDC 6000-series computer.

Algorithm 45. Automatic computation of improper integrals over a bounded or unbounded planar region

Abstract: An automatic quadrature algorithm especially designed for double integration of functions with some form of singular behaviour on the boundary of the integration region is described, and its FORTRAN code is presented.

Computational Chemistry: An Introduction to Numerical Methods

Abstract: A practical introduction to numerical methods that shows how to formulate a chemical problem in mathematical terms and select a numerical method to solve it. Introduces more powerful program sources such as the Numerical Algorithms Group (NAG) library, Contains worked examples and a wide range of problems varying in length and complexity, many of which require computer solutions using existing FORTRAN programs or subroutines listed in the appendixes.

Problem Solving and Structured Programming in Fortran

Abstract: Problem solving and structured programming in FORTRAN , Problem solving and structured programming in FORTRAN , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی

The Design of MIDAS - A Modular Interactive Data Analysis System

Abstract: A specialized computer facility, designed to provide a highly interactive, graphics-oriented, multi-user environment for the high-speed reduction and analysis of experimental data, is currently Under construction at Lawrence Berkeley Laboratory. The major difficulties in achieving high-speed data analysis (CPU limitations and I/O band-width restrictions) are minimized with MIDAS by using multiple CPU's to parallel-process the data and by utilizing multiple I/O busses with intelligent controllers to permit parallel, asynchronous data transmission to external memory blocks, which then may be switched dynamically to any processor. For data reduction, MIDAS should provide a processing power of about one CDC 7600 per user. Software utilization of the parallel architecture will be relatively transparent to the user, with analysis codes written in Fortran. Prototype tests of this facility are scheduled for summer, 1981.

An interactive FORTRAN IV program for calculating power, sample size, or detectable differences in means

Abstract: In designing experiments, the question of power arises in at least three common forms. The most common question asked is (1) \"How many subjects must 1 have in each group?\" A more sophisticated form of the power question is (2) \"If there are real differences among the populations sampled, what is the probability that I will find the differences significant?\" The answer to the second question is defined as the power of an experiment. Perhaps the most sophisticated expression of the power question is (3) \"Given my experimental design, what size differences am I likely to find significant?\" Answers to the above questions are not simple, since power is controlled by four basic parameters: (1) sample size, (2) alpha level, (3) population variance, and (4) actual differences that exist between the population means of the groups. To calculate a value for any of the above factors at a given power, or to calculate power itself, the remaining parameters must be fixed. For example, to answer the first question regarding necessary sample size, one must supply values for alpha, power, population variance, and the actual differences to be detected among the populations. Thus any computation regarding power depends on being able to make reasonable estimates of important aspects of the experiment in question. Cohen (1977) points out that the almost universal neglect of power planning by researchers is due in large part to the relative inaccessibility of the necessary tables and techniques, which are scattered throughout the statistical literature, and the mathematical sophistication required to use these materials. Even Cohen's simplified tables require some calculation, and interpolation is often necessary for practical problems. To perform power calculations, the present program queries the user for the necessary information, providing alternate forms of input when possible. By changing the values of input parameters within reasonable limits, the researcher can quickly put together a picture of the power characteristics of the plarmed research. The program first asks for the number of groups and the alpha level. The user is then asked to estimate his anticipated mean square error (this can often be done from a previous ANOVA on a similar experiment or pilot study). If the mean square error is not known, the program requests the estimated population standard deviation. The user then selects which of the three questions he wants answered. If, for example, sample size is to be computed, the user is asked to supply expected group means. If this cannot be done, the range between the largest and smallest means is requested. If no response is given, or if the user was unable to estimate the error term or standard deviation earlier, the range between means in standard deviation units is required. Last, the desired power is entered and the program displays the necessary sample size. Other options, if selected, are approached in a similar interactive manner. This program has proved helpful in a number of ways. First, when trying to advise researchers regarding the power aspects of their projects, it is difficult to explain that power calculations are complex. The researcher usually feels that there should be a simple answer to ''What n do I need?\" On the other hand, if the researcher sits in front of a CRT, then the complexities of power become immediately obvious. It becomes clear that one must have considerable knowledge regarding the planned research to assess power with reasonable accuracy. The program is also quite valuable in teaching students in statistics courses how power works. Finally, the program allows the user to plan his/her research, and since the program is interactive, there is no need for instruction manuals or tables. Power is calculated using the following approximate formula from Zelen and Severo (1965, p. 948):

FORTRAN for contemporary numerical computation

Abstract: In addition to the integers, the real and complex numbers, the real segments (intervals) and complex segments as well as vectors and matrices over all of these comprise the fundamental data types in computation. We extendFORTRAN so that it accepts operands and operators for all of these types as primitives in expressions.

A Fortran to Pascal translator

Abstract: This paper describes some of the problems encountered in implementing an automatic Fortran to Pascal translator. The translator introduces a number of improvements to the Fortran program including the structured control statements of Pascal. It highlights the structure of both COMMON blocks and executable statements, and it nests the Fortran subprograms to their required level.

Describing software design in Ada

Abstract: Ada is a tool suitable for the efficient and reliable development of solutions to a large problem domain. To combat the FORTRAN mind set and exploit the full power of the language, top down functional methodo logies are insufficient, and thus an object-oriented methodology is required. This paper provides some observations on such a methodology with subsequent representation of software design in the Ada Programming Support Environment (APSE).

A FORTRAN Computer Program for Calculating the Prolate Spheroidal Angular Functions of the First Kind

Abstract: : The Helmholtz wave equation (sq del + sq K) psi = 0 is separable in prolate spheroidal coordinates (eta, xi, psi) with the solution psi = R(c, xi) S(c, eta)Phi(phi) Here c = ka/2, where a is the interfocal distance A computer program called PANGFN has been developed to numerically evaluate in double- precision arithmetic the angular function of the first kind S(ml)(1) (c, eta) for any desired values of c, m, l, and the argument Theta = ARCCCOS(eta) The program is written in universal FORTRAN and should run on any computer that accepts this language Special techniques are used to avoid overflow and underflow problems By the use of logarithms, PANGFN can compute the angular function even when its value exceeds the exponent range of the computer This report describes the principle features of PANGFN Included are discussions of the significant FORTRAN variable names, dimensions and storage, parameter input, parameter ranges, computational procedure, computation time, printed output, and accuracy of the results A sample output and a computer listing of LINPRO are attached as appendices

Optical aberration coefficients: FORTRAN subroutines for symmetrical systems.

Abstract: FORTRAN computer subroutines for the automatic computation of the optical aberration functions S, T, V, W, and K to the 15th order for rotationally symmetric systems are presented. The routines may be conveniently extended toward higher orders.

Computer assisted teaching of FORTRAN

Abstract: An interactive programming system (FCN) which was developed to assist the teaching of FORTRAN is decribed. The educational advantages to be drawn from the incremental compilation of FORTRAN programs are discussed; specialized subsystems that can be used for intensive training during the early stages of an introductory course are presented. The intended role of this programming system and its contribution to the curriculum are discussed.

An algebraic front-end for the production and use of numeric programs

Abstract: We describe a programming environment which combines the Macsyma algebraic manipulation system with convenient and direct access to numeric Fortran run-time libraries. With this system it is also convenient to generate, compile, load, and invoke totally new Fortran programs which may have been produced by combining algebraically derived formulas and program “templates”. These facilities, available on VAX-11 computers, provide an environment for the generation and testing of advanced scientific software. Enhancements of Fortran for high-precision calculations, interval arithmetic, and other purposes are also supported.