期刊名称：ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences
印刷版ISSN：2194-9042
电子版ISSN：2194-9050
出版年度：2010
卷号：XXXVIII Part 4
出版社：Copernicus Publications
摘要：An area cartogram is a transformed map on which areas of regions are proportional to statistical data values; it is considered to be apowerful tool for the visual representation of statistical data. One of the most familiar cartograms is a circle (or circular) cartogram,on which regions are represented by circles. Dorling first proposed a circle cartogram construction algorithm in 1996 according tothe requirements ‘avoid overlap of circles’ and ‘keep contiguity of regions as much as possible’. The algorithm first places circlesaccording to the geographical configuration of regions and then moves them one by one in order to fulfil the requirements. It outputsresults which express a spatial distribution of data; however, the relative positions of circles on cartograms sometimes greatly differfrom the geographical maps. Cartogram readers usually compare the shape of cartograms to that of geographical maps, realize theshape distortion, and recognize the characteristics of spatial distribution of represented data on cartograms; removing the excesscircle reposition process from the algorithm is preferable to make the relative position of circles on resultant cartograms as similar aspossible to that on the geographical map. In this paper, I propose a new construction method for circle cartograms that attaches ahigh value to the preservation of relative position of circles while considering the requirements proposed by Dorling. I formulated aconstruction problem for non-linear minimization with inequality constraint conditions and applied the method to the worldpopulation dataset.
关键词：Circle Cartogram; Construction; Visualization; Distribution of Spatial Data; Non-linear Minimization with;Inequality Constraint
