Kris Garrett

Postdoctoral Research Associate
Los Alamos National Laboratory
ckgarrett@lanl.gov

Interests

Numerical Solutions to Kinetic Transport Equations
High Performance Computing
Numerical Linear Algebra

Papers

• A Nonlinear QR Algorithm for Unstructurally Banded Nonlinear Eigenvalue Problems
  C. Kristopher Garrett, Zhaojun Bai, and Ren-Cang Li
  ACM Transactions on Mathematical Software (2016)
  
• Optimization and Large Scale Computation of an Entropy Based Moment Closure
  C. Kristopher Garrett, Cory Hauck, and Judith Hill
  Journal of Computational Physics (2015)
• On the Eigenstructure of Spherical Harmonic Equations for Radiative Transport
  C. Kristopher Garrett, and Cory D. Hauck
  Computers and Mathematics with Applications (2015)
• GIP Integrators for Matrix Riccati Differential Equations
  C. Kristopher Garrett and Ren-Cang Li
  Applied Mathematics and Computation (2014)
• A Comparison of Moment Closures for Linear Kinetic Transport Equations: The Line Source Benchmark
  C. Kristopher Garrett and Cory D. Hauck
  Transport Theory and Statistical Physics (2013)
• Numerical Integration of Matrix Riccati Differential Equations with Solution Singularities
  C. Kristopher Garrett
  Ph.D. Dissertation (2013)
• Fast Polynomial Approximations to Sine and Cosine
  C. Kristopher Garrett
  Technical Report (2012)
  Software
• Neural Decoding and Modulation in Patients with Tetraplegia
  Problem 6 of the Sixteenth Mathematical and Statistical Modeling Workshop for Graduate Students (2010)
  Charles Kristopher Garrett, Matthew Labrum, Martial Longla, Guy-vanie Marcias Miakonkana, Varada Sarovar, Guolin Zhao
  Full Paper: http://www.ncsu.edu/crsc/reports/ftp/pdf/crsc-tr10-16.pdf

Software

• KeyValueReader
  A simple utility class for C++ to read key/value pairs from a file.
• Closures-2D
  Simulates explicit 2D kinetic transport solves with discrete ordinate approximations and spherical harmonic approximations. The spherical harmonic approximations include filtered spherical harmonics and entropy based closures. This code was used for A Comparison of Moment Closures for Linear Kinetic Transport Equations: The Line Source Benchmark.
• C3D-2015
  Implements an entropy based closure for spherical harmonics in 3D. Used for the 3D scaling study in Optimization and Large Scale Computation of an Entropy Based Moment Closure.
• Unstructured Banded Nonlinear Eigenvalue Solver
  Used for A Nonlinear QR Algorithm for Unstructurally Banded Nonlinear Eigenvalue Problems.
• L2 Polynomial Approximations to Sine and Cosine
  Used for Fast Polynomial Approximations to Sine and Cosine.

C and C++ Best Practices

I am compiling some best practices to help scientists with C and C++ programming. You can find them here.