This book is not a book about numerical software, using C as the vehicle for presenting examples; rather it is a book about C and UNIX, with the presentation tied together by the numerical slant of the examples. Twenty percent of the book is devoted to an initial chapter on the basics of C. This is followed by another 20 percent devoted to a chapter using C to write the dot product, matrix addition, and Gaussian elimination. Virtually nothing is said about numerical issues such as when to use the partial pivoting included in the program and what the other choices are. Instead, the emphasis is on program structure issues such as modularity, orderly development, specification, and realization of I/O interfaces.

Chapters 3 and 4, which comprise 30 percent of the book, are devoted to numerically related I/O issues: exchanging data via UNIX pipes and graphics. The slant of the book away from high volume numerical computation is established by the encouragement to convert double precision numbers to character strings and back again in order to pass them between programs. It is suggested that “a faster interface is probably more desirable” for large applications, but this is not pursued. The graphics chapter is fairly extensive and treats such things as clipping and windowing as well as curve plotting. Neither perspective projection nor contouring for presenting functions of two variables is covered.

The final 30 percent of the book is devoted to one chapter on optimization and one on differential equations. Again the emphasis is on program design and structure, and the discussion of numerical issues is abridged. You will find the word stiff mentioned, but techniques for handling stiff differential equations are beyond the scope of this book.

While this book handles modularity and interfaces fairly well, it has a number of peculiarities I tend to associate with C programming. In the main program for vector optimization, for example, the call to the routine that the text later identifies as “the heart of the vector optimization module” is buried in the condition of an if statement and identified only by the comment

• :2V*

• error in method occurred

• */