Pathway information display device

A directed graph layout apparatus for automatically laying out a directed graph configured by nodes and directed edges, comprising:

• a synthetic vector generation unit of generating a synthetic vector of all unit vectors, the unit vectors being the directed edges connected to each of the nodes;
• an angle correcting force generation unit of generating an angle correcting force for the each node serving as a connection destination node of the directed edges in a direction in which an angle between the synthetic vector generated at the synthetic vector generation unit and each of the unit vectors is smaller and in a direction perpendicular to the each unit vector;
• an energy calculation unit of calculating an energy by calculating a sum of the angle correcting forces for all the nodes;
• and
• an optimization control unit of changing a position of each of the nodes so as to optimize the energy calculated at the energy calculation unit.

A directed graph layout method for automatically laying out a directed graph configured by nodes and directed edges, comprising:

• a synthetic vector generation step of generating a synthetic vector of all unit vectors, the unit vectors being the directed edges connected to each of the nodes;
• an angle correcting force generation step of generating an angle correcting force for the each node serving as a connection destination node of the directed edges in a direction in which an angle between the synthetic vector generated at the synthetic vector generation step and each of the unit vectors is smaller and in a direction perpendicular to the each unit vector;
• an energy calculation step of calculating an energy by calculating a sum of the angle correcting forces for all the nodes;
• and
• an optimization control step of changing a position of each of the nodes so as to optimize the energy calculated at the energy calculation step.

A program capable of making a computer execute a directed graph layout method for automatically laying out a directed graph configured by nodes and directed edges, comprising:

• a synthetic vector generation step of generating a synthetic vector of all unit vectors, the unit vectors being the directed edges connected to each of the nodes;
• an angle correcting force generation step of generating an angle correcting force for the each node serving as a connection destination node of the directed edges in a direction in which an angle between the synthetic vector generated at the synthetic vector generation step and each of the unit vectors is smaller and in a direction perpendicular to the each unit vector;
• an energy calculation step of calculating an energy by calculating a sum of the angle correcting forces for all the nodes;
• and
• an optimization control step of changing a position of each of the nodes so as to optimize the energy calculated at the energy calculation step.