ABSTRACT
In this chapter we introduce matrices as arrays of numbers and define their basic algebraic operations: sum, product, and transposition. Next, we associate to a matrix a digraph called the Ko¨nig digraph and establish connections of matrix operations with certain operations on graphs. These graph-theoretic operations illuminate the matrix operations and aid in understanding their properties. In particular, we use the Ko¨nig digraph to explain how matrices can be partitioned into blocks in order to facilitate matrix operations.
