Representing Cyclic Change in Polar Coordinate Systems
نویسندگان
چکیده
Many spatio-temporal phenomena (both natural and human) change in time cycles, e.g., seasonal change of weather and pattern of peoples daily activities, which required a cyclic view of time. However, most GIS systems and cartographic representation adopt Cartesian Coordinate Systems (CCSs), which force time to be perceived as a linear dimension. Therefore, the cyclic change cannot be effectively represented in CCSs. This paper thus proposes the use of Polar Coordinate Systems (PCSs) to represent the phenomena with cyclic changes. In a PCS, polar angles are used to represent cyclic time, which can be clock time at daily, monthly or yearly resolution; polar distances are applied to represent moving extensions of the phenomena in two-dimensional space. The examples of yearly temperature of a city and human activity patterns are used to illustrate how cyclic changes can be represented in a PCS.
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