| Spatiotemporal trajectory data is the most representative data in this Big Data Era,which contains rich information.In order to mine this information to the greatest extent,many data analysis technologies came into being.Visual analysis is a means of data analysis.By using appropriate visualization methods to express trajectory data,users can obtain rules and knowledge more quickly.At present,a large number of visualization methods have been accumulated in academia to express trajectory data,such as statistical map,heat-map,density clustering map,trajectory flow map,spatiotemporal cube map,etc.These visualization methods are widely used by professional.However,under the background of new media and public cartography,more and more public have a certain demand for visual analysis of trajectory data.Due to lack of professional knowledge,ordinary users are often unable to quickly select the appropriate visualization method to express data,resulting cannot solve the problem efficiently.At present,the research of trajectory data visualization focuses on the innovation and application of visualization methods.Few scholar pay attention to the selection of visualization methods.Thus,this paper aims to build the selection model of visualization methods of trajectory data.The research contents and conclusions of this paper mainly include:(1)This paper proposed the conceptual model of visualization methods of spatiotemporal trajectory data.The research expounds the different connotations of spatiotemporal trajectory data from three aspects of point,line and surface,and then constructs the basic expression forms of spatiotemporal trajectory data under different connotations.Based on the spatial characteristics of visualization methods,the existing visualization methods of spatiotemporal trajectory data are classified.Based on the four basic elements of the data structure,the spatial morphological characteristic,the application technology and the expression form of the visualization method,the four tuple description system of the visualization method of spatiotemporal trajectory data is constructed,which is the conceptual model of the spatiotemporal trajectory data visualization.(2)This paper constructed the selection model of visualization methods of spatiotemporal trajectory data.The selection of spatiotemporal trajectory data visualization method is summarized,and its concept and basic process are expounded.Referring to the theory of Ontology and Domain Ontology,four tuple elements and visualization method itself are regarded as the concept set of ontology selection.The attributes and relationships of concepts are defined to construct the selection ontology of spatiotemporal trajectory visualization method.Then,the software Protégé is used to implement the above model,and specific examples are added by the software Neo4 j to generate the knowledge map of the selection of visualization method of trajectory data.(3)This paper carried out case study on the selection of spatiotemporal trajectory data visualization methods.Based on the analysis of residents’ travel characteristics,the selection conditions of visualization methods are extracted from many cases,such as residents’ travel space hotspots,space-time hotspots,cross region travel characteristics,and so on.Based on the selection model,the appropriate visualization methods are selected and analyzed,which shows the practical feasibility of the selection model in this paper. |
