Fast Map-making Oriented Research On Thematic Map Symbol Generation

Accompanied with the development of economies, thematic maps are playing a more and more important role in our lives. Symbolization is one of the key processes of thematic map making. However, nowadays, the study on relationship of data and symbol is not thorough. The theory on creating of thematic map can't meet the new needs because the maneuverability is not so good. The style of thematic map symbols is single. Original and harmonious symbols are lack. So it can't fulfill the needs of individual map making and affection map making. And the progress of thematic map making is difficult. The level of automatization and intelligence needs to be improved.Aiming at the problems above, in view of the needs of thematic map fast making, this paper studies the theory and technologies of thematic map symbol generation.1,Analyzing the problems of symbolization progress at the aspects of theory, technology and application. By looking back the development of computer assistant map making, this paper brings up the concept of"fast making", and discusses its characters and contents.2,The types and visual variables of thematic map symbols are studied. And the rules of the symbols composition are analyzed weightily. Then, two characters of thematic map symbols are brought up. They are data relativity and handsome diversity.3,Based on the rules of the symbols composition and in views of the characters of computer map making, it brings up the concept of symbol constitution variables. Then the meanings and multi-expression forms of symbol constitution variables in the environment of electronic map are analyzed and summarized, which settles the theory base of symbol fast generation.4,Based on the symbol constitution variables, the basic theory of symbol generation and three generation modes are put forward. The generation modes have three kinds which are generation modes of symbol constitution variables, generation modes of basic graph and generation modes of statistic symbols. What is more, the application methods and rules are analyzed safely. And it settles base of symbol fast generation technology.5,Module of symbol fast generation is actualized and it is integrated in GIS. The process of thematic map making is realized, which validates the former theory.