Method of storing a topological network, and methods and apparatus for identifying series of 1-cells in a network stored by such a method
First Claim
1. A computer-implemented method for arranging digital data representing a topological network in a memory, the network comprising a set of 0-cells (nodes) and a set of 1-cells and being divided into sections, a boundary node being defined at each point where the network traverses a boundary between sections, comprising:
- storing discrete parcels of data corresponding to each section of the topological network in a mass memory;
for a given section, storing in the data parcel a chain list record for each 1-cell in the section andstoring in each chain list record for a 1-cell terminating at a non-boundary node, a reference to a further 1-cell in the same section of the network terminating at the same node, such that no chain list record in a data parcel refers directly to a 1-cell outside the section of the network to which that data parcel relates.
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Accused Products
Abstract
A topological network, comprising a set of 0-cells (nodes) (28, 29) interconnected by a set of 1-cells (aa, bb, . . . , gg)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.
46 Citations
20 Claims
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1. A computer-implemented method for arranging digital data representing a topological network in a memory, the network comprising a set of 0-cells (nodes) and a set of 1-cells and being divided into sections, a boundary node being defined at each point where the network traverses a boundary between sections, comprising:
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storing discrete parcels of data corresponding to each section of the topological network in a mass memory; for a given section, storing in the data parcel a chain list record for each 1-cell in the section and storing in each chain list record for a 1-cell terminating at a non-boundary node, a reference to a further 1-cell in the same section of the network terminating at the same node, such that no chain list record in a data parcel refers directly to a 1-cell outside the section of the network to which that data parcel relates. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A computer readable storage medium embodying a data structure for storing electronic map data, the electronic map being composed of a plurality of discrete parcels, each parcel comprising at least one 1-cell and at least two 0-cells, the data structure comprising:
a plurality of respective chain lists, each respective chain list being for listing 1-cells from a respective one of the discrete parcels, each 1-cell being stored with an indication of 0-cells which are end points of the 1-cell, none of the chain lists containing any reference to any feature of any discrete parcel other than the respective discrete parcel; and
a plurality of respective node lists, each respective node list being for listing 0-cells for a respective one of the discrete parcels, each 0-cell being stored with an indication of those 1-cells within the respective discrete parcel that are connected with that 0-cell, at least one of the 0-cells being also stored with an indication of a connection to a 0-cell outside the respective discrete parcel, none of the node lists containing any reference to a 0-cell outside the respective discrete parcel.- View Dependent Claims (17, 18, 19, 20)
Specification