| 摘要 |
PURPOSE:To easily perform a data management by controlling the deletion of an objected data to be operated and a related data using a relation and the content of the relation between data stored at a storage device in a data operation time. CONSTITUTION:A graphic data 3 dealt in a CAD system 2, etc., has a close relation between the data, and the data having no meaning is present unless other related data is present. For example, when a polyhedron is expressed with a data structure centering a ridgeline, a vertex data includes the ridgeline which sets the said vertex as an endpoint. Therefore, when all of the ridgelines are deleted, the vertex should be deleted. In a general data, a means which defines the kinds of the relation between data in a graphic data structure definition 31 time, and in a graphic data operation 32 time, it is controlled whether a deletion process is performed or not by the kind of the relation. Thereby, it is not more required to delete an unnecessary data, the data related to which is not present, by a user program, and the data process at the user program can be easily performed.
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