Method of storing a topological network, and methods and apparatus for identifying series of 1-cells in a network stored by such a method

摘要

A topological network, comprising a set of 0-cells (nodes) (28, 29) interconnected by a set of 1-cells (aa, bb, . . . , gg).sub.1 is divided into sections (E, F, G) corresponding to discrete parcels of data for storage in a mass memory such as a CD-ROM. A boundary node (28, 29) is defined at each point where the network traverses a boundary between sections. The parcel of data for a given section includes a chain list record for each 1-cell in the section, which chain list record generally refers directly (TP) to a further 1-cell in the network terminating at the same node. However, no chain list record refers directly to a 1-cell outside the section of the network to which the data parcel relates. An indirect reference (0-C') across the section boundary can be made easily, while an overall saving in data volume is obtained compared with a known method. Further information can be introduced into the data parcels by ordering techniques, enabling the network data to be used in a particularly efficient and systematic manner.