| The Fortran 90 standard represents the first significant change in Fortran in over 20 years,
and brings it into line with most modern structured programming languages. This book is
one of a handful on Fortran 90, and one of even fewer in which every program (unless
otherwise clearly stated) has been tested on a working compiler: the FTN90 compiler for
PCs.
If you are a newcomer to Fortran, you should read the book in the conventional way, from
the beginning.
However, if you are a Fortran 77 user you may like to dip immediately into later chapters to
see some of the new features of the language. Probably the two most important advances
are the new array facilities (Chapters 9 and 15) and the impressively enlarged collection of
intrinsic procedures (Appendix C), including the so-called elemental functions which
operate on all or selected elements of array arguments. You may now define your own
types, or structures (Chapter 12) and even construct linked lists with them using pointers
(Chapter 13). Modules (Chapter 8) may be independently compiled, and may contain type
definitions and variable declarations, as well as procedures. The use of interface blocks
(Chapter 8) makes it possible to overload specific procedure names with generic names,
and also to overload operators. Conditional loops are possible now with DO WHILE
(Chapter 6), and there is a new CASE statement (Chapter 6). However, you should
probably first have a look at Sections 2.2--2.5 (program layout, variable declarations, etc.)
and Section 3.5(kind) to see some important changes in the basics of Fortran.
In keeping with the spirit of the earlier edition, this book is a problem-solving exposition of
Fortran 90, and not a technical reference manual. You will therefore not necessarily find all
the references to a particular topic in one place in the text (e.g.\ arrays are covered in
Chapters 9 and 15) as this would interfere with the informal style of the book. There are,
however, appendices with summaries of all the statements and the intrinsic procedures,
and a comprehensive index.
I should like to thank the following in particular: David Mackin of Edward Arnold for his
helpful editorial suggestions, and for arranging the loan of an FTN90 compiler; Peter
Anderton of The Numerical Algorithms Group for the loan of the compiler; the University of
Cape Town for leave in order to write this book, and for financial support for the project; my
long-suffering colleagues for leaving me alone while I was writing; and my wife, Cleone,
who patiently reminds me when programs won't work, that computers are like that, aren't
they? |
