CGL Meeting Agenda

Wednesday, September 10th, 1997

Location:
DC 1304
Time:
13:30
Chair:
Peter Harwood

1. Adoption of the Agenda - additions or deletions

2. Coffee Hour

Coffee hour this week:
Dunno.
Coffee hour next week:
Dunno.

3. Next meeting

Date:
September 17th, 1997
Location:
Computer Graphics Lab (DC 2303)
Time:
13:00
Chair:
Rob "Freddy" Kroeger
Technical presentation:
John Ousterhout (visitor to UW -- see Seminars below)

4. Forthcoming

Chairs:

  1. Celine Latulipe (9/24)
  2. Marryat Ma (10/1)
  3. Leo Magalhaes (10/8)
  4. Mike Hammond (10/15)

Tech Presenters:

  1. Peter Harwood (9/24)
  2. Celine Latulipe (10/1)
  3. Marryat Ma (10/8)
  4. Leo Magalhaes (10/15)

5. Technical Presentation

Presenter:
Michael McCool
Title:
Finding Roots with the Interval Newton Algorithm
Abstract:
Root finding is a fundamental operation in many computer graphics algorithms, most prominently ray/surface intersection in ray tracing. Yet algorithms that are both fast and robust are relatively difficult to achieve for otherwise arbitrary continuous functions.

When some properties of a function are known, such as its regions of monotonicity, then a robust scalar root-finding algorithm such as reguli-falsi can be used, perhaps in conjunction with bracketed Newton interval steps. If nothing is known about the function, then the interval Newton method can be used to prove the monotonicity properties needed to get such a fast ``scalar'' method started.

The interval Newton technique requires a bound on the derivative of the function over an interval. For arbitrary functions, this can be accomplished with various interval arithmetics and automatic differentiation. For splines, tight derivative bounds can be found via control value differencing, subdivision, and the convex hull property.

In this talk I will present the Newton interval root-finding technique and discuss its properties and an implementation.

6. General Discussion Items

7. Action List

8. Director's Meeting

9. Seminars


ICR/PAMI Joint Seminar
----------------------
``On-Line Fingerprint Verification''
Anil K. Jain, Computer Science, Michigan State University
10:30 a.m.; DC1302


ICR SHORT COURSES:
------------------

ICR Members and Graduate Students supervised by ICR faculty members may
attend free-of-charge subject to availability.
Registration required: detailed info is available at the ICR Web site:
http://icr.uwaterloo.ca

September 16-17, 1997
    ICR Short Course
    ``Software Engineering Practice: An Industry Perspective''
    Jacob Slonim, Adjunct Professor, Computer Science, U. of Waterloo
    9:30 a.m. - 4:30 p.m.; DC1304


Celebrity Lecture Series in Computer Science
--------------------------------------------

Sponsored by the CSGSA

SPEAKER: John Ousterhout
	 Sun Microsystems Laboratories

TITLE:	``Scripting:  Higher Level Programming for the 21st Century.''

DATE:	Wednesday, September 17, 1997

TIME:	1:30-2:30 p.m.

ROOM:	DC 1302

ABSTRACT

As we near the end of the 20th century a fundamental change is occurring in 
the way people write computer programs. The change is a transition from system 
programming languages such as C or C++ to scripting languages such as Perl or 
Tcl. Although many people are participating in the change, few people realize 
that it is occurring and even fewer people know why it is happening. In this 
talk I will explain why scripting languages will handle many of the 
programming tasks of the next century better than system programming languages. 
Scripting languages represent a very different style of programming than system 
programming languages. They are designed for "gluing" applications, and use type
less approaches to achieve a higher level of programming and more rapid 
application development. Increases in computer speed and changes in the 
application mix are making scripting languages more and more important for 
applications of the future.

10. Lab Cleanup (until 14:30 or 5 minutes)