Edge Routing with Fixed Node Positions

The two basic problems of graph drawing - drawing of nodes and drawing of edges - are often handled by one algorithm that finds suitable positions for both nodes and edges. However, there are situations where positions of nodes are fixed, for instance if they were defined by the user or the exact position of the nodes is somehow significant. In these cases we need an algorithm that draws only the edges no matter what the positions of the nodes are. This paper presents one such algorithm. We present the very basic version of the algorithm followed by two ways of improving it to produce better looking and clearer results.