【摘要】 传统的树结构数据存储是按元素的大小关系,而对于工程结构CAD中的图元不好定义大小关系,给树结构应用带来不便。因此改变树结构的存储方式,将树结构按分级分类方式存储,并给出了一种图形元素的分级等价关系,用等价关系对图元进行分类。采用这种存储方式,能方便地提取具有某一特征的子结构树、删除树结点、分级分类插入树结点等操作。给出的算例表明分级分类的存储能提高搜索速度、方便进行分级分类的子结构树的数据处理,这种树结构存储方式适用于定义有分级等价关系的数据。更多还原

【Abstract】 The traditional storage of tree data structure is according to the relation of the elements’ frant-and-back. Since it is difficult to define the frant-and-back relation of graphics units in CAD for Engineering structure, the application of the tree structure becomes inconvenient. The authors change the storing method for the tree structure into gradation and classification. And a graded equivalence relation of graphics units is brought forward, which grade the graphics units with the equivalence relation. By using this storing method, we can easily accomplish some operations, such as picking up the subtree with a certain character, deleting a node, insert a graded and classified node, etc. The example provided indicates that the storage by gradation and classification can speed up searching and process the data of the subtree by gradation and classification expediently. This kind of storing method for the tree structure is applicable for data which contain the graded equivalence relation.更多还原