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Accuracy of Count Data Estimated by the Point‐in‐Polygon Method
Author(s) -
Sadahiro Yukio
Publication year - 2000
Publication title -
geographical analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.773
H-Index - 65
eISSN - 1538-4632
pISSN - 0016-7363
DOI - 10.1111/j.1538-4632.2000.tb00416.x
Subject(s) - polygon (computer graphics) , point (geometry) , weighting , interpolation (computer graphics) , point in polygon , distribution (mathematics) , mathematics , algorithm , geometry , computer science , monotone polygon , mathematical analysis , artificial intelligence , image (mathematics) , medicine , telecommunications , frame (networking) , radiology
This paper analyzes the accuracy of count data estimated by the point‐in‐polygon method. A point‐in‐polygon interpolation model is proposed, based on a stochastic distribution of points and the target zone, in order to represent a variety of situations. The accuracy of estimates is numerically investigated in relation to the size of the target zone and the distribution of points, and the optimal location of representative points is discussed. The major findings of this paper are as follows: (1) though the relative accuracy of estimates generally increases monotonously with the size of the target zone, the monotoneity is often disturbed by the periodicity in the spatial configuration of source zones and the point distribution; (2) the point‐in‐polygon and the areal weighting interpolation methods have the same accuracy of estimates when points are concentrated in less than 12–15 percent area around the representative point in source zones; (3) the point‐in‐polygon method is not so robust against the locational gap between points and the representative point; (4) the optimal location of representative points is given by the spatial median of points.