N. da Silva, I. Carlos Alcântara de Oliveira

University Cruzeiro do Sul (BRAZIL)
Given the importance of graph theory to many fields and its practical application in modeling and solving problems, several researchers have dedicated time and effort to study and extend the concepts related to this area. With the advance of Computer Science, applications have been designed to work with graphs, facilitating the analysis of large amount of data, increasing knowledge and its use in different situations, such as route calculation, networking organization and logistics.
Based on information of other applications, such as, GoGraph, GraphAlg, GraphViz, Pigale and "graphs", and the subjects of Graph Theory, this paper presents the development of an application with the goal of facilitating the studying, analysis and learning of graph theory, called Graphe.
In the Graphe project, the UML language has been used. With the goal of enabling platform independence and subsequent use in mobile devices, the Graphe has been developed in the Java language. It also uses XML files to represent the graphs generated.
The Graphe has a simplified interface that allows the construction of graphically graphs by adding vertexes and edges using the mouse. It has elements that allows the contextualization of the data present in the graph, such as text boxes and images. It also performs analyzes about the generated graphs obtaining relevant information about its structure, such as connectivity, order, adjacency and incidence matrixes.
Other Graphe tools and resources are: the possibility to move and to align objects, export graphs to PNG image, upload several files at once allowing the user to view multiple graphs in tabs in the same window; the possibility to generate automatic graphs in certain layouts; and to zoom in graphs.
The Graphe also allows to run the algorithms on graphs previously built, or running them step by step. Then, it displays the results about the running algorithms and the state of the graph at each interaction performed. In the current version, the Graphe has the algorithms: depth search, width search and graph coloring.
Moreover, Graphe has an innovative feature, not found in other graphs applications. This resource allows the addition of new algorithms developed by the user without the need to recompile the entire application, which enables to expand the functionality of the application and test the implementation of many algorithms. To add the new algorithms, the user must have some knowledge about Java programming . These algorithms added by the user can: modify the graph previously built; access the graph information; and use these information in processing and visualization.
In addition to all these Graphe features, the innovative possibility of adding new algorithms provides flexibility to the application, allows students to further their studies in graph theory, creating and adding their own algorithms, and allows the teacher to request activities related to algorithms involving the study of graphs.