Table Of Content—-+ oe , FS = = — Ss
iY L
esl 2 — =F
Quick Index to FORTRAN 77
264 BACKSPACE unit
187 BLOCK DATA name
101 CALL sub_name (arg, {,...} {, arg,} )
145 CHARACTER {+ length} var_name {( subscripts )}
145 CHARACTER+«(*) var_name {( subscripts )}
149 CHARACTER+(*) FUNCTION function_name (arg, {,...} {, arg,} )
265,273 CLOSE ( unit {, STATUS = [‘KEEP’]/['DELETE’]} {, IOSTAT = check? )
182 COMMON / name /v ar_list
62,166 COMPLEX var_name {( subscripts )}
40 CONTINUE
70 DATA varib_name / const /
41 DO label varib = init, final {, step}
62 DOUBLE PRECISION var_name {( subscripts )}
16 ELSE
16 ELSEIF ( log_expr ) THEN
END
ENDFILE unit
ENDIF
label FORMAT ( field, {, . . .} {, field,} )
date_type FUNCTION function_name (arg, {, .. .} {, arg,} )
GOTO label
IF (log_expr ) THEN
INQUIRE ( [UNIT = unit]/[FILE = ‘file_name’]
{, ERR = error_label} {, EXIST = log_ exist}
{, NAMED = log_named} {, IOSTAT = check}
{, OPENED = log_opened} {, number = unit_numb}
{, NAME = file_name} {, ACCESS = char_access}
{, SEQUENTIAL = char_seq} ({, DIRECT = char_direct}
{, FORM = char_form} {, UNFORMATTED = char_unform}
{, RECL = rec_length} {, NEXTREC = next_numb}
{, BLANK = char_bla} )
62 INTEGER var_name {{ subscripts )}
120 (1/O_list, varib = init, final {, step} )
62 LOGICAL var_name {( subscripts )}
268,274 OPEN (unit {, FILE = ‘file_name’}
{, STATUS = [‘'NEW’]/[‘OLD’]}
{, FORM = [‘FORMATTED’]/['UNFORMATTED’]}
{, IOSTAT = check} )
(continued on inside back cover)
FROM PASCAL TO FORTRAN 77
APPLICATIONS FOR SCIENTISTS
AND ENGINEERS
DAVID DONALD MILLER
Bemidji State University
HARCOURT BRACE JOVANOVICH, PUBLISHERS
and its subsidiary, Academic Press
San Diego ¢ New York ¢ Chicago ¢ Austin
London ¢ Sydney ¢ Tokyo ° Toronto
FROM PASCAL
TO FORTRAN 77
APPLICATIONS
FOR SCIENTISTS
AND ENGINEERS
Microsoft is a registered trademark of Microsoft Corporation.
MS is a trademark of Microsoft Corporation.
HP and Touchscreen are trademarks of Hewlett-Packard.
DEC, VAX, and VMS are trademarks of Digital Equipment Corporation.
Copyright © 1987 by Harcourt Brace Jovanovich, Inc.
All rights reserved. No part of this publication may be
reproduced or transmitted in any form or by any means,
electronic or mechanical, including photocopy, recording,
or any information storage and retrieval system, without
permission in writing from the publisher.
Requests for permission to make copies of any part of the
work should be mailed to: Permissions, Harcourt Brace
Jovanovich, Publishers, Orlando, Florida 32887.
ISBN: 0-15-529175-0
Library of Congress Catalog Card Number: 86-70532
Printed in the United States of America
PREFACE
In recent years, the popular computer science programming textbooks
have been gradually swinging toward Pascal, primarily because computer
science concepts are easily taught and learned using Pascal. But other
disciplines, in particular engineering and the physical sciences, require a
knowledge of programming. In the engineering work-a-day world, pro-
gramming is firmly entrenched in FORTRAN for the following reasons:
= Because of its simple structures, FORTRAN is easy to use in some
applications.
= FORTRAN offers mathematical sophistication not available in
standard Pascal or in any Pascal extensions.
= FORTRAN supports a wide variety of file manipulation constructs
not available in standard Pascal.
Vv
vi — Preface
= A real-world application often involves a combination of several
subprograms, which is supported by the FORTRAN system but not
by Pascal.
= Because of its longevity, millions of lines of FORTRAN already exist
and must be maintained (modified, added to, and used).
= FORTRAN compilers are usually error free and generate optimized
code.
From Pascal to FORTRAN 77: Applications for Scientists and Engineers
is directed to those students who have been introduced to programming
through Pascal but whose career goals are in engineering or the physical
sciences. Such students will need a working knowledge of FORTRAN.
This textbook is also directed to practitioners who must make a transition
from Pascal to FORTRAN.
FORTRAN is a programming language of the ancients—it could even
be called a classical language, since in the world of computers 30 years is
quite a long time. And, just like an old house, it has acquired a whole attic
full of elaborate rules and special cases. Many of the original FORTRAN
constructions have been replaced over the years, because we know more
about compiler languages now than we did when FORTRAN was pi-
oneering the field. This book cuts through the historical bric-a-brac and
concentrates primarily on the most useful parts of FORTRAN. Inciden-
tally, many of the best parts of FORTRAN have Pascal counterparts as
well, and I will draw heavily on the student’s Pascal knowledge to show,
by example and counter-example, FORTRAN and Pascal code side by side.
The older FORTRAN constructions have been included, for the sake of
completeness, in an appendix, because students will surely see older ver-
sions of FORTRAN in their careers.
HOW TO USE THIS TEXTBOOK
The material moves along quickly, especially through the introductory
chapters. In fact, the student will be coding simple programs at the end
of the first chapter and writing serious FORTRAN by the end of the third
chapter. Each chapter contains the following features:
= A discussion of the chapter material, often including FORTRAN
program segments and the equivalent Pascal segment for
comparison.
Preface vil
m An example, including explanation, algorithm, commented code,
sample execution, and testing suggestions.
m ‘Pitfalls’ that a Pascal programmer and a novice FORTRAN
programmer would be likely to encounter.
@ Exercises that elaborate on the example and that introduce related
topics.
The text makes the following assumptions about the student’s level of
computer expertise: .
m It assumes the student has already been introduced to such primary
programming topics as basic computer architecture, interactive
terminal sessions, program structure, and the like. The student’s
time will not be wasted by the introduction of that kind of
information again, and the text will, instead, draw upon that
knowledge and extend it.
= It assumes the student is acquainted with problems that occur in
the physical world—some of the examples may have been seen in
other courses.
m Since this is a textbook for engineers and other physical scientists,
most of the examples and exercises are drawn from the scientific
and mathematical world; the student will never have to compute a
payroll. A few examples involve games, since programming should
be fun too. Some problems involve mathematics through calculus
and, in some cases, differential equations. But higher math is not
normally required, especially early in the text. The intention is to
introduce real-world problems, approaches, and software solutions,
and in doing so, to introduce topics like modeling functions, solving
systems of equations, and numerical integration. All of the students’
acquired mathematical skills should be brought into focus in this
course.
The last point requires some elaboration: Computer generated an-
swers tend to be believed without supporting evidence. This is an ex-
tremely dangerous attitude and one that should be corrected. A secondary
purpose of the text is to illustrate some introductory applications of
digital computing in a practical world. This is not supposed to be a nu-
merical analysis course, but it may well be the only exposure some stu-
dents will ever have to the subject. I am concerned that students learn
both the possibilities and the impossibilities of digital computation, and
that they be made aware of the misapplication of computers as well as
viii Preface
their applications. I have tried to impart a “feeling’’ for detecting unrea-
sonable answers—and have listed some heuristics that may help students
examine their code when they are suspicious of their answers.
One other thing: This book will force students to go back into some of
their ‘‘old” textbooks. Maybe they thought they would never have to open
them again, but I want them to know that education in a technological
world is never ending: Those texts are still valuable. Several of the exer-
cises are designed to send students into those other books to look up deri-
vations and formulas: I have not simply provided the necessary equation as
part of the exercise. That is how it is done in industry: Employees are given
a problem statement and it is up to them to define an approach and do the
necessary research.
This book concentrates on the standard, FORTRAN 77. Many of the
examples here are coded using VAX FORTRAN in the “‘standard’”’ FOR-
TRAN 77 mode. Several of the examples are also coded using MS-DOS
FORTRAN on the HP 150: Touch Screen. MS-FORTRAN is based on the
“subset” standard FORTRAN 77, which in this case also includes many
“full” standard features. It has its shortcomings, however, and when it is
appropriate, I warn the student of any implementation-specific snags that
I have discovered in the process. Maybe they will not have any trouble on
their particular machine and maybe they will have other problems.
ACKNOWLEDGMENTS
I wish to thank the following reviewers for their helpful suggestions: Bev-
erly Bilshausen, College of DuPage; Mark J. Christiansen, Georgia Insti-
tute of Technology; Larry Cottrell, University of Central Florida; Charlotte
Fischer, Vanderbilt University; Charles Gould, Florida Institute of Tech-
nology; Lawrence O. Hall, Florida State University; Larry Neal, Eastern
Tennessee State University; Charles Neblock, Western Illinois University;
Bob Pabasco, University of Idaho; Jim Pannell, DeVry Institute; Paul Paul-
son, Central Michigan University; Don Ramsey, Tennessee Technological
University; Paul Ross, University of Millersville; Richard Sleight, Univer-
sity of Washington; and Terry Smith, Northeastern University.
DAVID DONALD MILLER
