Patent ID: 8447790

Claim:
An electric device for executing a process based on a map data comprising: a map data memory for storing the map data; a work memory; and a CPU for reading out the map data from the map data memory and for developing the map data into the work memory as developed map data, the CPU is configured to execute the process based on the developed map data in the work memory, the map data in the map data memory provides a road network, which is defined by a plurality of unit links and a plurality of link connection relationships, the map data omits node data that describes nodes of the road network, each link represents a part of a road, each link connection relationship represents a connection between links at a connection point, the map data includes an attribution data in each link, the attribution data provides attribution of a corresponding link and attribution of an end of the corresponding link, the attribution of the end includes connection relationship information of the corresponding link at the end; generate a node table according to the attribution data, from the map data that omits the node data that describes nodes of the road network, the node table stores a link connection information in each node as the connection point coupled with a plurality of links, the link connection information provides identification of the plurality of links, which are coupled with each other at a corresponding node; and write the node table as the developed map data into the work memory.