A Hierarchical Display Method for AND-OR Graphs

Abstract

The invention discloses a hierarchical display method of an AND-OR graph, which includes: (1) creating the starting point and end point of the AND-OR graph; (2) reading in a data file, and constructing all the AND-OR graphs in the AND-OR graph according to the quadruple data file Model nodes and directed line segments form the internal model of the AND-OR graph; (3) Initialize, set the search flag of the node data object as unsearched; (4) Perform breadth-first search and display on the AND-OR graph model, starting from the starting point or Starting from the root node, search outward layer by layer and display each AND-OR graph node; (5) Extend processing, expand the static relationship graph so that it can dynamically display all nodes of the AND-OR graph. The method of the present invention can use the tree window commonly used in computer systems to display complex and multi-scheme AND-OR graphs, and by adding virtual nodes, the representation of complex AND-OR graphs can be more refined and clear without crossing lines, and is especially suitable for large-scale complex problems Or program representation and optimal solution.

Description

technical field [0001] The invention belongs to the technical field of computer graphics, and more specifically relates to a hierarchical display method of an AND-OR graph, which is used to display a two-dimensional AND-OR graph using tree-like display software commonly used in computer systems. Background technique [0002] For complex engineering problems, the problem is often decomposed into some independent small problems, and then they are solved separately. The AND-OR graph is a powerful tool to describe this engineering solution method, which is characterized by linking problems with parent-child relationships and decomposing sub-problems. Formally, all problems and sub-problems form a hierarchical structure, similar to a directed acyclic graph. Different from the directed acyclic graph, the AND-OR graph also includes an AND-OR relationship, because the decomposition of the problem does not have only one solution, and the AND-OR graph can simultaneously express multi...

AI Technical Summary

Problems solved by technology

[0010] 2) Graphical layout is difficult

Although manual drawing can provide a relatively perfect effect, the drawing efficiency is very low, and the crossing lines cannot be completely eliminated

[0012] 3) It is inconvenient to automatically draw the AND or relationship

This method is very refined and easy to understand, but it is not easy to realize automatic drawing in the computer system, because the connection between the parent-child relationship in the computer is usually a broken line, and it is not easy to distinguish between several broken lines. relation

[0014] 4) poor overall sense

[0015] When the number of directed graph nodes and directed line segments is relatively large, the size of the entire AND-OR graph will become very large, and the computer display screen is limited, which brings difficulties to use

If you look at the whole picture, you may not be able to see the text information on the picture clearly; if you look at a partial picture, it is difficult to form an overall impression

[0016] 5) It is troublesome to find

[0017] Similarly, when the number of nodes in the AND or graph is large, although the text can be zoomed in to see clearly, but at the same time the visible part is very small, it will be difficult to find nodes or directed line segments that are not within the current view range

When zooming out the content of the drawing, although you can quickly move the and or drawing, you must zoom in to confirm the content you need to find

[0018] 6) Graphic maintenance is difficult

[0020] In particular, it should be pointed out that no matter whether computer graphics are used or not, when recursion appears in the AND-OR graph, using the traditional method to draw the AND-OR graph may increase a lot of work because the recursive relationship cannot be fully utilized

E.g, figure 1 There are only 4 assemblies shown, and only 2 parts participate in each assembly, which will generate 12 nodes and 29 edges. If the number of parts that make up the product is relatively large, the number of parts participating in each assembly is not limited , the number of nodes and edges will be very large, so it will be difficult to guarantee the correctness when drawing the AND or graph

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