- Brian L. Evans,
Steve X. Gu,
Edward A. Lee, and
Philip Chen,
*Mathematica Notebooks to Accompany Contemporary Linear Systems*, PWS Publishing Company, ISBN 0-534-93509-5 (PC) and 0-534-93507-9 (Mac), 1995.

- Robert D. Strum and Donald E. Kirk,
*Contemporary Linear Systems Using MATLAB*, PWS Publishing Company, ISBN 0-534-93273-8, 1994.

Using the Mathematica Notebooks, *students* can

- manipulate formulas so as to solve linear systems problems that have symbolic as well as numerical and graphical answers;
- check hand calculations by asking the computer to show them the intermediate calculations involved in performing fundamental operations, such as convolution and z-transforms;
- work problems in multimedia environment using modern word processing capabilities instead of a command-line interface;
- check answers by asking the computer whether an answer is correct or not, and receive hints about what they might be doing wrong if the answer is not correct; and
- have access to the complete solution to the reinforcement and exploration problems, expressed in Mathematica commands when appropriate.

Using the Mathematica Notebooks, *professors* can

- cut-and-paste the electronic solutions to create customized solution sets for homework assignments
- challenge the students to think about using computers to solve problems that are algebraic and not just numeric in nature
- show the students the intermediate steps in algebraic computations.

The product comes with limited technical support, manual installation instructions, and no printed user or reference manuals. It is, however, electronically documented by means of 20 Mathematica notebooks. Two of the notebooks serve as an introduction to Mathematica and to the Signal Processing Packages, respectively. Each pair of remaining notebooks corresponds to one chapter in the textbook. One notebook of each pair works the example problems, rephrases the homework problems, and automatically checks student answers to the homework problems. The other notebook in each pair explains the solutions to the homework problems.

The PWS product contains Version 3.0 of the Signal Processing Packages, which were released April 28, 1995, and are compatible with versions 2.0, 2.1, and 2.2 of Mathematica. The Notebooks in the PWS Product, however, are only compatible with Mathematica 2.2. The PWS product requires 13 Mb of disk space, and Mathematica should be configured to run in at least 12 Mb of memory. Macintosh and PC (Windows) versions are available. Unix and Windows 95 users should order the PC (Windows) version. For compatibility, Windows 95 users will also need the package TruncCon.m, which they will need to evaluate before loading the Signal Processing Packages.

In the electronic companion, the Signal Processing Packages and Notebooks are copyright © 1989-1995 Georgia Tech Research Corporation. The notebooks and the package ``StrumKirk.m'' are copyright © 1994-1995 Regents of the University of California.

Send comments to Brian Evans at bevans@ece.utexas.edu