Efficient Range Reporting of Convex Hull
نویسندگان
چکیده
We consider the problem of reporting convex hull points in an orthogonal range query in two dimensions. Formally, let P be a set of n points in R. A point lies on the convex hull of a point set S if it lies on the boundary of the minimum convex polygon formed by S. In this paper, we are interested in finding the points that lie on the boundary of the convex hull of the points in P that also fall with in an orthogonal range [xlt, xrt] × [yb, yt]. We propose a O(n log n) space data structure that can support reporting points on a convex hull inside an orthogonal range query, in time O(log n + h). Here h is the size of the output. This work improves the result of (Brass et al. 2013) [5] that builds a data structure that uses O(n log n) space and has a O(log n+h) query time. Additionally, we show that our data structure can be modified slightly to solve other related problems. For instance, for counting the number of points on the convex hull in an orthogonal query rectangle, we propose an O(n log n) space data structure that can be queried upon in O(log n) time. We also propose a O(n log n) space data structure that can compute the area and perimeter of the convex hull inside an orthogonal range query in O(log n) time.
منابع مشابه
Sweep Line Algorithm for Convex Hull Revisited
Convex hull of some given points is the intersection of all convex sets containing them. It is used as primary structure in many other problems in computational geometry and other areas like image processing, model identification, geographical data systems, and triangular computation of a set of points and so on. Computing the convex hull of a set of point is one of the most fundamental and imp...
متن کاملL-CONVEX SYSTEMS AND THE CATEGORICAL ISOMORPHISM TO SCOTT-HULL OPERATORS
The concepts of $L$-convex systems and Scott-hull spaces are proposed on frame-valued setting. Also, we establish the categorical isomorphism between $L$-convex systems and Scott-hull spaces. Moreover, it is proved that the category of $L$-convex structures is bireflective in the category of $L$-convex systems. Furthermore, the quotient systems of $L$-convex systems are studied.
متن کاملOn Generalized Planar Skyline and Convex Hull Range Queries
We present output sensitive techniques for the generalized reporting versions of the planar range maxima problem and the planar range convex hull problem. Our solutions are in the pointer machine model, for orthogonal range queries on a static point set. We solve the planar range maxima problem for two-sided, three-sided and four-sided queries. We achieve a query time of O(log n+c) using O(n) s...
متن کاملOn Constructing Approximate Convex Hull
The algorithms of convex hull have been extensively studied in literature, principally because of their wide range of applications in different areas. This article presents an efficient algorithm to construct approximate convex hull from a set of n points in the plane in O(n+ k) time, where k is the approximation error control parameter. The proposed algorithm is suitable for applications prefe...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- CoRR
دوره abs/1307.5612 شماره
صفحات -
تاریخ انتشار 2013