Koushi Anzai

Hierarchical program diagram editor based on attribute graph grammar

The hierarchical program diagram editor is a tool for visual program environments. We propose a model of a syntax-directed diagram editor using an attribute graph grammar We formalize and define editor commands by using productions of the attribute graph grammar which defines the hierarchical program diagram. This guarantees that any diagram that is grammatically correct can be generated and that there will be no syntax errors in the program generation and editing processes with the editor. We have implemented our editor based on the editor command definitions. The system is the first practical program diagram editor supporting complete syntax-directed commands and efficient automatic layouts by using attribute graph grammars. The methods should be applicable to development environments for various tree-structured diagrams.

Block diagram generation and parsing based on graph grammar

A block diagram is a graphical model with which it is possible to concisely visualize a system structure and is widely used in control engineering and other fields. However, there are few studies that try to formulate a syntax of block diagrams. In this research, we define a block diagram grammar which generates block diagrams by means of subgraph rewriting of a graph grammar. It includes some context-sensitive productions and is very concise. We have also developed a parser based on this block diagram grammar that parses a diagram in a bottom-up parallel method. It decides whether a diagram is valid for the grammar or not, and returns a production instance sequence for a valid diagram.

8k-ary Grid graph models of tabular forms

Tabular forms are commonly used in software. Those tabular forms are represented as rectangular dissections. In rectangular dissections, ruled line oriented operations such as cell merge, line and column operations are often used. With respect to ruled line oriented operations, 8k-ary grid graphs have been introduced as models of rectangular dissections that provide fast algorithms. This paper surveys octal and hexa-decimal grid graph models of rectangular dissections. First, octal grids, called octgrids, for single layer rectangular dissections and related algorithms are introduced. Next, hexa-decimal grid graphs for multiple layer rectangular dissections, called hexadeci-grids, and related algorithms are introduced. Furthermore, tetraicosa-grid graphs for rectangular solid dissections for CG applications, called tetraicosa-grids and related algorithms are introduced.

Depth-first layout algorithm for trees

Abstract This paper deals with a layout problem of trees satisfying certain given aesthetic conditions. It is known as “tidy drawing problems of trees”. We consider a type of tree called a “tree-structured diagram” in which each node has variable size and location. In this paper, for drawing tree-type program flowcharts, we first formulate “tidy drawing problems of tree-structured diagrams” on the integral lattice. The formulation defines a tree-structured diagram and aesthetic conditions, which are modifications of the tidy drawing problem of trees. Second, we develop O(n)- and O(n2)-time algorithms to provide layouts which satisfy the conditions introduced. As a result, we obtain the relationship between the aesthetic conditions and the time complexity of algorithms.

Block diagram grammar and structure recognition based on graph rewriting

A block diagram grammar is presented that is a formal model generating block diagrams. It is formalized as a context-sensitive graph grammar with subgraph rewriting based on subgraph isomorphism. We implement a block diagram parser that decides whether a diagram is valid for the block diagram grammar in a bottomup-parallel method, and that returns the production instance sequence for a valid diagram. A function of structure recognition is also implemented into the parser by means of template matching and subgraph rewriting. This enables the parser to find and return the structure information of series connections, parallel connections, feedback connections and so forth, in the parsed diagram.

A method of drawing tree-structured program diagrams on the Euclidian plane

A tree-structured diagram is considered as a tree in which each node has four attributes: (1) width, (2) depth, (3) horizontal coordinate and (4) vertical coordinate. The placing problem of the tree-structured diagram satisfying certain given eumorphous conditions is called a tidy drawing problem. The eumorphous conditions of tree-structured diagrams, oriented to program diagrams, have been formulated by modifying the eumorphous conditions of trees. formalized eumorphous conditions and corresponding unformalized methods of placement on the integral lattice were developed by Ogura etal. (1992). In this paper, we introduce new eumorphous conditions on the Euclidian plane. We also formulate O(n)-time and O(n/sup 2/)-time practical algorithms to provide placements which satisfy new eumorphous conditions by modifying the former conditions on the integral lattice As a result, we have new relationships among the eurmorphous conditions.<<ETX>>

A graph grammar model for syntaxes of financial statements

We deal with a formalization of financial statements. In order to formalize financial statements, we have to specify the spatial order of items, and specify calculation methods. In this paper, we construct a context sensitive graph grammar to specify the order of items of financial statement. Furthermore we also append attribute rules to the context-sensitive graph grammar to specify calculation methods.

An XML Representation of the Octgrid for the Rectangular Dissections

This paper proposes an XML representation of octgrid completely. Octgrid is a data structure based on octal grid graphs for heterogeneous rectangular dissections. This model is represented by a list structure called H3-Code. The file format of H3-Code is a plain text file that consists of a plurality of space separated field. Therefore we introduced the XML representation called H14-Code.

A multi-layer rectangular dissections and the list structures for the 16-ary grid graph

Heterogeneous rectangular dissections are frequently used in information processing such as multiple paged books in spread sheet languages and multi-layer image data. In previous studies, a hexadecimal grid graph model was proposed for multilayer rectangular dissections and certain algorithms were provided. In this paper, we propose a 16-ary list structure to implement their algorithms for the hexadecimal grid graph model. The list structure has limited number of fields in a record, so the computation time is low. Furthermore, it has one record for each node in the given hexadecimal grid, and 48 fields for each record. We also show a data format of the whole structure of the list.

A formalization of financial statements with heterogeneous parts by graph grammars

We deal with a formalization of financial statements which is a type of business documents. In order to formalize financial statements, we have to specify the order and number of items, and specify calculation methods. In this paper, we construct a context-sensitive graph grammar to specify the order of items of financial statement with heterogeneous parts. We also show examples of derivation.