Computational Geometry 202-2-5121
Fall 2016

Prerequisite: Algorithms


Announcements:


Instructor:

Matya Katz  ( matya@cs.bgu.ac.il

Office hours: Sunday 12:00-14:00, Alon building (37), room 212, Tel: (08) 6461628

 

Teaching Assistant:

          Omrit Filtser

 

Class Time:

Tuesday 14-16 (building 34, room 5)

Thursday 12-14 (building 34, room 5)


Course Description:

This is an introductory course to computational geometry and its applications. We will present data structures, algorithms and general techniques for solving geometric problems, such as convex hull computation, line segment intersection, orthogonal range searching, construction of Voronoi diagram and Delaunay triangulation, polygon triangulation, and linear programming. We will also present several geometric (optimization) algorithms to problems in robotics, computer graphics, GIS (geographic information systems), communication networks, facility location, and VLSI systems design.
 


Bibliography:

The main textbook of the course is

[dBCvKO] Computational Geometry: Algorithms and Applications (3rd edition),
M. de Berg, O. Cheong, M. van Kreveld and M. Overmars, Springer-Verlag, 2008.
 

Additional textbooks

[BY] Algorithmic Geometry, J-D Boissonnat and M. Yvinec, Cambridge University Press, 1998.

 

[DO] Discrete and Computational Geometry, S. Devadoss and J. O’Rourke, Princeton University Press, 2011.

[E] Algorithms in Combinatorial Geometry, H. Edelsbrunner, Springer-Verlag, 1987.

[M] Computational Geometry: An Introduction Through Randomized Algorithms, K. Mulmuley, Prentice Hall, 1994.

[O] Computational Geometry in C (2nd edition), J. O'Rourke, Cambridge University Press, 1998.

[PS] Computational Geometry: An Introduction (2nd edition), F. Preparata and M. Shamos, Springer-Verlag, 1988.


Assignments, Exam and Grades:

The final grade will be determined by 3-5 homework assignments (4% each) and a final exam.

 

Many of the exercises in the HW assignments are taken from [dBCvKO].

 

Assignment no. 1 (due November 27, 2016)

Assignment no. 2 (due December 20, 2016)

Assignment no. 3 (due January 10, 2017)

Assignment no. 4 (due January 26, 2017)

 

 

 

Some old exams: exam 2005 A; exam 2005 B; exam 2007 A; exam 2007 B; exam 2009 A; exam 2009 B


Topics:

The following list of topics is tentative.

The convex hull of a set of points in the plane (applications: computing the diameter and width of a point set).

An output sensitive algorithm for computing the intersection points formed by a set of line segments; the plane sweep technique.

A representation for planar maps (based on doubly-connected edge lists).

Computing the overlay of two planar maps; boolean operations on two polygons (union, intersection, and difference).

The art gallery theorem; introduction to polygon triangulation.

An O(n log n) polygon triangulation algorithm (partitioning a polygon into y-monotone pieces; triangulating a y-monotone polygon).

Orthogonal range searching.  

Computing the intersection of n half planes in O(n log n) time.

Linear programming - introduction; A randomized incremental algorithm for linear programming in the plane.

Planar point location, vertical decomposition / trapezoidal map, a randomized incremental algorithm.

Nearest site queries, nearest site Voronoi diagram.

Triangulation of a set of points in the plane; the Delaunay triangulation.

Arrangement of lines; duality; computing the discrepancy of a set of points in the unit square.

Segment trees; computing the area of a set of n axis-parallel rectangles in O(n log n) time.

Hidden surface removal: problem definition, image space / object space, the z-buffer algorithm, depth order,   the painter's algorithm. Output sensitive hidden surface removal algorithm for horizontal fat triangles.  

Introduction to geometric optimization through facility location optimization and wireless networks.

Measures of similarity between curves.

 


Course summary:

Below you will find, after each class, a brief summary of the topics covered in class.
This should not be taken as a complete description of the course's content.


1.11.16
Introduction

 

3.11.16

The convex hull of a set of points in the plane (gift wrapping, quickhull, an O(n log n)-time incremental algorithm and a divide and conquer algorithm (homework))

 

8.11.16

The diameter of a set of points; rotating calipers. The width of a set of points (homework)

 

10.11.16

Sweeping; an output sensitive algorithm for line segment intersection

 

15.11.16

Generalizations of the line segment intersection algorithm, sweeping with a ray

 

17.11.16

Implementing the decision problem “do two line segments intersect?” and a more general discussion on implementation issues and general position; The doubly-connected edge list representation for planar maps 

 

22.11.16

Map overlay (sketch); Boolean operations; The art gallery theorem

 

24.11.16

Introduction to guarding problems; Introduction to polygon triangulation

 

29.11.16

Partitioning a polygon into y-monotone pieces; triangulating a y-monotone polygon

 

1.12.16

Orthogonal range searching, kd-tree

 

6.12.16

Orthogonal range tree

 

8.12.16

Segment tree

 

13.12.16

Computing the area of the union of axis-aligned rectangles; Intro to linear programming

 

15.12.16

Computing the intersection of n half planes in O(n log n) time.

Linear programming - A randomized incremental algorithm for LP in the plane

 

20.12.16

Planar point location, vertical decomposition, a randomized incremental algorithm

 

22.12.16

Planar point location – continued

 

27.12.16

Voronoi diagram

 

29.12.16

Triangulation of a point set, Delaunay triangulation

 

3.1.17

Delaunay triangulation - continued

 

5.1.17

Duality, arrangements of lines

 

10.1.17

TSP and variants, Christofides approx. algorithm

 

12.1.17

Intro to covering and piercing problems

 

17.1.17, 19.1.17

Fatness – definitions and algorithms for point enclosure and hidden surface removal


Last update: January 23, 2017