Quantum harmonic oscillator                                    Me, among friends                                                                   Red Oak

Barton Willis

Professor of Mathematics
2142 Founders Hall
University of Nebraska at Kearney
Kearney, NE 68849
willisb at unk dot edu

At UNK, I've taught college algebra (MATH 102), trigonometry (MATH 103), calculus (MATH 123, 115, 202, 260), foundations of mathematics (MATH 250), differential equations (MATH 305), linear algebra (MATH 440), numerical analysis (MATH 420), abstract algebra (MATH 350), and advanced calculus (MATH 460). At other universities, I've taught classes in partial differential equations and engineering mathematics (including statistics).

Computer Algebra

I'm a developer for the Maxima computer algebra system. I wrote or co-authored Maxima packages for finite sets (NSet), combinatorics, linear algebra, orthogonal polynomials, Fourier elimination, and solutions to second order linear differential equations. Also, I wrote the code for the conjugate, floor, ceiling, to_poly, mod, min, and max functions. To download Maxima (it's free!) or to learn about Maxima, visit Maxima at Sourceforge. If you have questions about how to use Maxima, send a note to the Maxima mailing list.

Maxima Code

• Here (odelin19.tar.gz) is Maxima code for solving second order linear differential equations. It uses a method of Bronstein and Lafaille.
  
• batTeX is a hacked version of Maxima's continue function that allows LaTeX code to contain embedded Maxima commands. The function batchlatex evaluates the Maxima commands and formats them with TeX. Sample output is here. And some documentation is here.

Academic Things I do

In addition to teaching classes, I advise about one dozen mathematics and mathematics education majors; I maintain the department's web page; and
I'm a consulant for the MAA's project NExT. When I can, I invent new mathematics.

Some Miscellaneous Things I have Written

• I don't gamble. Here is an essay I wrote about an article that was published in a mathematics journal on a scheme for placing bets on a horse race. The mathematics in the paper is correct, but it ignores the fact that the theory shows that the bets should really be negative! The journal published a retraction.

• Here are some slides (in postscript) for a talk I gave at a local MAA meeting on the condition number and numerical fuzz.

• Here are some slides for a talk I gave at a regional MAA meeting on the Maxima Computer Algebra Project.

• Here is my solution to problem 10795, ``Three-dimensional Lattice Walks in the Upper Half-Space,'' from the American Mathematical Monthly. Unlike the solution published in the December 2001 issue, my solution uses generating functions and Cauchy's integral formula.

• Here is an article that gives two methods for finding eigenvalues and eigenvectors without using determinants; and here are slides slides from a talk
  "A Determinatless Existence" I gave to faculty and students at UNK.
  
  
• Here is an essay I wrote for a calculus class about finite and infinite sums.
  
  
• And an essay about using set notation in undergraduate mathematics education.
  
  

   

Biographical Sketch

I grew up on a farm in the Kansas Flint Hills. For several years, I attended a two room grade school in Keats, Kansas. After graduation from Riley County High School, I attended Kansas State University, where I earned a Bachelor of Science degree in Mathematics and Physics (dual major). After graduation, I studied mathematical physics at Virginia Tech, where I was a student of University Distinguished Professor Paul Zweifel. In 1985, I earned a Ph.D. from Virginia Tech, and since 1992, I've taught mathematics at the University of Nebraska at Kearney (UNK).

Non-Academic Things I Do

True to my farm background, I enjoy digging up my yard and replacing the grass with flowers, vegetables, and berries. Having lived in the South for a dozen years, I got hooked on collard greens and okra. These vegetables aren't always available in Kearney, but they grow well in Nebraska. I like growing wildflowers that are native to the Great Plains and to the Rocky Mountains. Some of my favorites are Agastache,Aquilegia,Monarda,P enstemon, Rudbeckia, and Echinacea. I also like the challenge of growing azaleas in Nebraska's alkaline soil. Every fall, I plant a few hundred tulip bulbs; a few years ago, I helped plant about two hundred tulip bulbs near A.O. Thomas Hall on the UNK campus.

I do volunteer gardening for a non-profit organization that is near my home. If you are starved for attention, try strolling through suburbia carrying garden implements.

I hike anywhere there are mountains and trees. I first visited Rocky Mountain National Park when I was four years old and I still love to hike there. I've climbed Mt. Handies (14,068 feet), Mt. Chiquita (13,069 feet), Hallet Peak (12,713 feet),  Mount LeConte  (6,593 feet), and Mount Rogers (5,729 feet), but mostly I like just being outside in nature.

A few years ago, I started taking art classes with a local artist; I enjoy drawing with colored pencils and painting with watercolor. My Grandmother was an artist and my mother was a highly skilled crafts person, so maybe there is some hope for me.

I'm the founding member of the Kearney Introverts Club (KIC).  We don't have meetings or events. I know of two other members; everybody is welcome to join.

A few years ago, I acquired my first orchid. My beginners luck is starting to fade, but I'm hooked nevertheless.