Introduction
The transfer matrix method (TMM) is a powerful modeling approach for distributed parameter systems, especially those under feedback control. However, it is not very well known. Because the TMM involves matrices and states, it is sometimes mistakenly thought to be similar to the ubiquitous state-space approach. Transfer matrices do not represent how the states relate to their first-order derivatives like state-space matrices do. Instead, transfer matrices describe how the boundary conditions are transfered spatially from one end of an element to the other. In a sense, transfer matrices could be thought of as capturing the spatial portion of partial differential equations of distributed parameter systems.