More Pictorial Representations

Abstract

A network diagram is a system of nodes and connections, also called devices and wirings respectively. The nodes are drawn as circles or boxes whereas the connections are drawn as connected systems of lines or arrows. Each node has an ordered collection of connection points on its boundary. The endpoints of a connection (wiring) can be tied to the connection points of the nodes. We shall restrict ourselves to directed networks, i.e. networks where each connection is a system consisting of arrows. Figure 8.1 illustrates the difference between a

graph and a network. The graph has four nodes a, b, c, and d and four directed edges. Each edge goes from one node to one other node. The network has four nodes p, q, r and s, and five connections (wirings). The first wiring feeds from a loose outermost connection point into the two input connection points of p as well as the two input connection points of r. Then there is a connection that feeds the output of p into the upper inputs of q and s. Another connection feeds the output of r into the lower inputs of q and s. Finally there are two connections with a loose end.

For centuries painters composed by natural form and colour; at present the composition itself is the plastic expression, the image. (P. Mondrian)