Showing papers on "Choropleth map published in 1985"
01 Oct 1985-Cartographica: The International Journal for Geographic Information and Geovisualization
TL;DR: In this article, the authors focus on data representation accuracy of choropleth maps and show that three factors, enumeration unit size, enumerations unit compactness, and variability of the distributions mapped are significant in determining enumeration units aggregate value accuracy and map accuracy.
Abstract: Accuracy of thematic maps is identified as having two components: planimetric accuracy and data representation accuracy. The first is of only minor concern for thematic maps. Data representation accuracy, however, is at least as significant to map effectiveness as are the perceptual and cognitive aspects of map reading that have been given so much attention in recent years. The focus of the study presented is on data representation accuracy considering the specific case of choropleth maps. It is demonstrated that three factors, enumeration unit size, enumeration unit compactness, and variability of the distributions mapped are significant in determining enumeration unit aggregate value accuracy and, therefore, map accuracy. Based on experimental results, it is suggested that potential accuracy of choropleth maps could be predicted through measurement of these characteristics. A second experiment is used to demonstrate the applicability of this method to predicting overall choropleth map accuracy as well a...
22 citations
NEC1
TL;DR: In this article, a graphical user interface, called "Histogram Interface", is implemented as countermeasure for problems in designing choropleth maps, which can assist map designers in representing their ideas and achieving the desired maps through the designing process.
Abstract: Problem analysis in designing thematic maps and user interfaces which assist map designers in incorporating their ideas into maps are presented.
Problems in designing choropleth maps are analyzed from the map designers point of view. A graphical user interface, called "Histogram Interface", is implemented as countermeasure for problems in designing choropleth maps. The user interface can assist map designers in representing their ideas and achieving the desired maps through the designing process. The user interface operations, which correspond to the map designer's ideas, are explained. The user interface effectiveness is confirmed by resulting map examples and the corresponding graphical patterns on the interface.
A concept is proposed concerning the importance in any computer graphics field, which the designers should consider in determining how to incorporate their ideas into pictures.
10 citations
1 Jan 1985
TL;DR: In this paper, the boundaries of the hydrologic cataloging units for the United States were digitized from a 1:2,500,000 scale map and the data set produced is continuous across the conterminous United States, and should be very useful for national and regional studies of water resources.
Abstract: Boundaries of the hydrologic cataloging units for the United States were digitized from a 1:2,500,000 scale map. The data set produced is continuous across the conterminous United States, and should be very useful for national and regional studies of water resources and displays of choropleth maps of data applicable to the units.
1 citations