Book Reviews 317

in depth, reference is made specifically to IBM file organisations for direct, indexed and relative files implemented in IBM OS/W Cobol. This constitutes about one third of the book and I have some doubts as to whether it is really worthwhile exploring the subject in so much depth given that the fine detail is only relevant to an IBM file user. Readers flicking through this central portion of the book might well wonder if they had picked up an IBM self-teaching manual rather than a general text on Cobol programming.

The next three chapters contain detailed consideration of the COPY statement, the use of the source program library, external subprograms and character manipulation. As well as giving details and examples of syntax the author considers the merits and disadvantages of use and also points out common potential mistakes and misunderstandings.

The penultimate chapter discusses changes associated with ANS Cobol X3.23.1985. There are some very useful examples demonstrating the implications of these changes.

The book concludes with an introduction to Cobol in an interactive environment. As well as comparing interactive and batch processing the chapter contains a brief discussion of the hardware and software environments required for interactive systems. It makes use of specific reference to the IBM CICS system as an example of a teleprocessing monitor.

Overall the book contains numerous practical hints for the programmer, adopting a realistic approach in warning of the dangers associated with the advanced Cobol syntax it discusses and containing useful brief notes on such matters as coding standards. Whilst, as mentioned above, I feel a somewhat excessive amount of space appears to have been allocated to the discussion of file handling, there is much to recommend this book either as an introductory text to the topics covered or as a study aid.

Thomson Directories Farnborough Hants England

ANNE FRANCIS

Problem Solving with FORTRAN 77: BRIAN D. HAHN. Edward Arnold, 247 pp. E8.95 (paperback).

This is another text setting out to teach the basics of a programming language and, while doing so, to impart elements of software design. The target audience is undergraduates, for whom this book will be good value as it also includes several useful programs, as well as ending each chapter with a summary of the areas covered and a set of exercises.

After two introductory chapters, which the busy student could omit, the third chapter presents a large proportion of the FORTRAN language through the use of examples. This is followed by a few pages in which flow charts and structure plans are described. The use of the DO statement for code repetition is covered, taking examples from classical dynamics and electricity. The building up of familiarity with the language proceeds with branching code using IF, IF-THEN-ELSE and nested IFS. Various examples given previously in the book are re-worked using these statements. To implement a WHILE loop, as FORTRAN 77 does not include the explicit statement, the author makes use of the GOT0 statement. There follows a useful chapter which discusses the sources of errors.

The next group of chapters begins with a treatment of the FORTRAN statements which define the format of data being read and written, including a paragraph defining a “file”. Progress is then made on the methods available in FORTRAN for describing and manipulating arrays. The way in which FORTRAN handles characters is then described. In the twelfth chapter, that vital aid to software design, the SUBROUTINE, is introduced.

The final two chapters are devoted to applications of FORTRAN 77 in the areas of simulation, matrix applications and differential equations. The examples presented include random-walk, matrix multiplication, solution of simultaneous linear equations and solution of linear differential equations.

An epilogue is included which summarises the style implicit in the samples given throughout the book.

318 Book Reviews

“Problem Solving with FORTRAN 77” ends with a summary of FORTRAN statements. The text is well printed, with FORTRAN keywords in bold type and programming examples in a clearly-differential typeface. On the whole this is useful text, and good value.

St Albans Herts England

BRIAN WISHART