Page numbers impose a one-dimensional organization on any book. I placed basic things early in the book, important things in the middle of the book, and theoretical, less frequently used things at the end. Within chapters and sections, this book answers the questions what and how before it answers why. I chose to avoid a strictly logical organization because that would result in too much math at the beginning and too long a delay before the reader encountered applications. Thus, you may read about a single subject at different points in the book. It is not organized like an encyclopedia but is ordered for learning. For reference, please make use of the index.