Precision and robustness in geometric computations

Abstract

Accuracy and precision are 2 diff terms. This paper is only interested in precision; accuracy of gis data is another problem that is solved by other people.(p. 256) "correctness is often replaced by robustness. Robustness is a measure of the ability to recover from error conditions, e.g. tolerance of failures of internal components or errors in input data."(p. 257) "Pertubation of the input is justified by the fact that in many geometric problems the numerical data are real world data obtained by measuring and hence known to be innacurate. This is certainly true for most of the geometric problems in GIS."(p. 257) "Since precision problems are caused by degenerate and nearly degenerate configurations in the input, degeneracy is closely related to precision and robustness."(p. 261) "Geometric predicates test properties of basic geometric objects. They are used in conditional tests that direct the control flow in geometric algorithms".