Fredrik Johansson's website
Contact: fredrik.johansson@gmail.com
I'm interested in arbitrary-precision arithmetic, polynomial arithmetic, and computation of special functions. I'm the main author of mpmath and Arb, and coauthor of FLINT.
Starting in September 2014, I'm a postdoc at Inria Bordeaux-Sud-Ouest and Institut de MathÃ©matiques de Bordeaux, working in the LFANT project-team headed by Andreas Enge and Karim Belabas.
From 2010 to 2014, I did my PhD in symbolic computation at RISC, Linz, where Manuel Kauers was my advisor. I have an MSc in engineering physics from Chalmers University of Technology, Gothenburg. I was born in Sweden.
Updates
Publications
This list is also available in BibTeX format (txt file).
- F. Johansson. Efficient implementation of elementary functions in the medium-precision range. Submitted. [PDF] [arXiv]
- R. P. Brent, F. Johansson. A bound for the error term in the Brent-McMillan algorithm. To appear in Mathematics of Computation. [PDF] [arXiv]
- F. Johansson. A fast algorithm for reversion of power series. Mathematics of Computation, vol 84, 2015, 475-484. [PDF] [arXiv] [DOI] [info]
- F. Johansson. Fast and rigorous computation of special functions to high precision. PhD thesis, RISC, Johannes Kepler University, Linz, 2014. [PDF] [info]
- F. Johansson. Evaluating parametric holonomic sequences using rectangular splitting. ISSAC 2014, 256-263. [PDF] [slides] [arXiv] [DOI] [info]
- F. Johansson, B. Nakamura. Using functional equations to enumerate 1324-avoiding permutations. Advances in Applied Mathematics, vol 56, 2014, 20-34. [PDF] [arXiv] [DOI] [info]
- F. Johansson. Rigorous high-precision computation of the Hurwitz zeta function and its derivatives. Numerical Algorithms, 2014. [PDF] [arXiv] [DOI] [info]
- M. Kauers, M. Jaroschek, F. Johansson. Ore polynomials in Sage. To appear in Computer Algebra and Polynomials, Springer Lecture Notes in Computer Science. [PDF] [arXiv] [info]
- F. Johansson. Arb: a C library for ball arithmetic. ACM Communications in Computer Algebra, vol 47, issue 4, December 2013, 166-169. [PDF] [slides] [DOI] [info]
- F. Johansson, M. Kauers, M. Mezzarobba. Finding hyperexponential solutions of linear ODEs by numerical evaluation. ISSAC 2013, 211-218. [PDF] [arXiv] [DOI] [info]
- F. Johansson. Efficient implementation of the Hardy-Ramanujan-Rademacher formula. LMS Journal of Computation and Mathematics, vol 15, 2012, 341-359. [PDF] [arXiv] [DOI] [info]
Mathematical software
- mpmath - Python library for arbitrary-precision floating-point arithmetic (main author, since 2007)
- Arb - C library for arbitrary-precision ball arithmetic (main author, since 2012)
- FLINT - C library for number theory (coauthor, since 2010)
- ore_algebra - Sage package for holonomic functions (coauthor, 2013)
- Sage (miscellaneous contributions since 2009)
- SymPy (miscellaneous contributions 2007-2008, designed the logo)
Talks
- September 2014: Reliable multiprecision arithmetic for number theory, LFANT seminar, IMB, Bordeaux
- July 2014: Evaluating parametric holonomic sequences using rectangular splitting, ISSAC 2014, Kobe University, Japan
- May 2014: Making change for 10^{20}, seminar, TU Kaiserslautern
- March 2014: Making change for 10^{20}, Algorithmic Combinatorics Seminar, RISC, Hagenberg
- October 2013: Progress on algorithms for high-precision evaluation of special functions, Algorithmic Combinatorics Seminar, RISC, Hagenberg
- July 2013: Efficient implementation of the Hardy-Ramanujan-Rademacher formula, 2013 SIAM Annual Meeting, San Diego, CA
- June 2013: Arb: a C library for ball arithmetic, ISSAC 2013, Boston, MA [Received the ISSAC 2013 Distinguished Software Presentation Award]
- June 2013: Finding Hyperexponential Solutions of Linear ODEs by Numerical Evaluation, ISSAC 2013, Boston, MA
- March 2013: Fast, rigorous, arbitrary precision numerics with ball arithmetic, Algorithmic Combinatorics Seminar, RISC, Hagenberg
- November 2012: Algorithms for hyperexponential solutions of differential equations, Algorithmic Combinatorics Seminar, RISC, Hagenberg
- May 2012: Fast special function computations with FLINT, RISC-DESY Workshop, RISC, Hagenberg.
- December 2011: Fast combinatorial special functions, Sage Days 35: Algorithms in Number Theory and FLINT, University of Warwick
- November 2011: Partitions in the quintillions or Billions of congruences, Algorithmic Combinatorics Seminar, RISC, Hagenberg
- November 2011: Fast reversion of power series, Algorithmic Combinatorics Seminar, RISC, Hagenberg
- July 2010: Computation of special functions in mpmath, Sage Days 24: Symbolic Computation in Differential Algebra and Special Functions, RISC, Hagenberg
- July 2010: Computation of special functions in mpmath, Sage Days 23: Number Theory and Algebra, Lorentz Center, Leiden
- May 2009: mpmath: arbitrary-precision floating-point arithmetic and special functions, Sage Days 15, University of Washington, Seattle, WA
Music
- I compose MIDI music.
- What I'm listening to: my last.fm account.
Doom
My Doom maps and related information.