### Graduate Student Seminar, 4:30 pm September 13, 2004; HH127

#### Speaker:

Dan Bates
#### Title:

Polynomials in Practice
#### Abstract:

Two years ago, I discussed some of the latest techniques for solving polynomial
systems numerically. Last year, I gave everybody a "small dose of polynomial
history and culture". Now, in the third installment of this very drawn out
k-part series (with 2<k<7), I will discuss how to use polynomials in practice,
i.e., on computers.

Basic to any software that manipulates polynomial systems is the internal
representation of the polynomials. I will describe some of the ways that
polynomials are stored by computer programs (some clever, some not at all) and
will focus especially on the advantages of a representation known as the
straight-line program. I will demonstrate some wonderful tools, known as yacc
and lex (or bison and flex for you open source people), that can be used for
parsing polynomials into straight-line programs. If there is time remaining, I
will dazzle you with the concept of automatic differentiation. Don't worry - I
will not assume any programming background!

To volunteer to give a talk, or for any other questions regarding this schedule,
contact Sara Miller