I ransform methods provide a unifying mathematical approach to the study of
electrical networks, devices for energy conversion and control, antennas, and other
components of electrical systems, as well as to complete linear systems and to
many other physical systems and devices, whether electrical or not. These same
methods apply equally to the subjects of electrical communication by wire or op-
optical fiber, to wireless radio propagation, and to ionized media—which are all con-
concerned with the interconnection of electrical systems—and to information theory
which, among other things, relates to the acquisition, processing, and presenta-
presentation of data. Other theoretical techniques are used in handling these basic fields
of electrical engineering, but transform methods are virtually indispensable in all
of them. Fourier analysis as applied to electrical engineering is sufficiently im-
important to have earned a permanent place in the curriculum—indeed much of the
mathematical development took place in connection with alternating current the-
theory, signal analysis, and information theory as formulated in connection with elec-
electrical communication.