Author Archives: Brent

About Brent

Assistant Professor of Computer Science at Hendrix College. Functional programmer, mathematician, teacher, pianist, follower of Jesus.

Finding roots of polynomials in Haskell?

Posted on February 13, 2019

tl;dr: There are several Haskell packages one can use to find an individual root of a function on a certain interval. But I’ve had less luck finding a suitable package for finding all the roots of a given polynomial. This … Continue reading →

Posted in haskell, math | Tagged , , , , , | 4 Comments

Hendrix teams at ACM ICPC

Posted on November 4, 2018

Today I took five students from Hendrix to Fort Smith to compete in the Mid-Central USA Regional of the ACM International Collegiate Programming Contest (ICPC). Both teams solved five out of ten problems, and finished second and fourth out of … Continue reading →

Posted in meta, teaching | Tagged , , , , | Leave a comment

What’s the Difference? video and slides

Posted on October 20, 2018

At ICFP in St. Louis I presented my paper with Kenny Foner, What’s the Difference? A Functional Pearl on Subtracting Bijections. Many people seemed to enjoy the talk and we got lots of great feedback afterwards. We will probably write up … Continue reading →

Posted in combinatorics, haskell, writing | Tagged , , , , , , | Leave a comment

Counting inversions with monoidal sparks

Posted on October 6, 2018

Time for me to reveal the example I had in mind that led to the generalization in my previous post. Thanks for all the interesting comments: it seems like there are some interesting connections to be explored (e.g. to the … Continue reading →

Posted in math | Tagged , , , , , , , , | 7 Comments

Monoidal sparks

Posted on October 1, 2018

While at ICFP in St. Louis this past week, I discovered an interesting construction on monoids that no one I talked to (including Kenny Foner and Edward Kmett) seemed to have heard of or thought about before. In this post I’ll … Continue reading →

Posted in math | Tagged , , , , | 27 Comments

New ICFP functional pearl on subtracting bijections

Posted on June 23, 2018

Kenny Foner and I have a paper accepted to ICFP on subtracting bijections. Here’s the basic problem: suppose you have a bijection between two sum types, , and another bijection . Of course and must have the same size, but … Continue reading →

Posted in combinatorics, haskell, writing | Tagged , , , , , | 5 Comments

Ertugrul Söylemez: 1985-2018

Posted on May 21, 2018

I do not know many details, but IRC user mupf joined the #haskell-ops channel yesterday to tell us that Ertugrul Söylemez died unexpectedly on May 12. This is a great loss for the Haskell community. Going variously by mm_freak, ertes, … Continue reading →

Posted in haskell, meta | Tagged , , , , | 4 Comments