1.8 Evaluating Examples in This Guide
When evaluating examples in this guide on your computer system, you may sometimes find that your results differ somewhat from the documentation. Differences in symbolic expressions may come from different heuristic rules employed in different versions of Mathematica; they usually vanish after a simplification. Small numerical residuals may be different because of the different machine arithmetic. Further, some numerical results may be different if a numerical algorithm, also based on the machine arithmetic, selects another possible value from the universe of equivalent values. In such cases, you can usually confirm that you are still getting a correct result by testing some property of the resulting system (e.g., eigenvalues of the closed loop system after a pole placement). Finally, the concrete values after random distortions will, of course, be different in your experiments.