14 citations · 20 across the 9 of their papers we have counts for
10 papers
Estimation When Both Covariance And Precision Matrices Are Sparse
Shev Macnamara, Erik Schlögl, Zdravko I. Botev
We offer a method to estimate a covariance matrix in the special case that \textit{both} the covariance matrix and the precision matrix are sparse --- a constraint we call double s…
Positivity-preserving methods for population models
Sergio Blanes, Arieh Iserles, Shev Macnamara
Many important applications are modelled by differential equations with positive solutions. However, it remains an outstanding open problem to develop numerical methods that are bo…
The reflectionless properties of Toeplitz waves and Hankel waves: an analysis via Bessel functions
Kevin Burrage, Pamela Burrage, Shev MacNamara
We study reflectionless properties at the boundary for the wave equation in one space dimension and time, in terms of a well-known matrix that arises from a simple discretisation o…
Kernel Density Estimation with Linked Boundary Conditions
Matthew J. Colbrook, Zdravko I. Botev, Karsten Kuritz +1
Kernel density estimation on a finite interval poses an outstanding challenge because of the well-recognized bias at the boundaries of the interval. Motivated by an application in…
Wider contours and adaptive contours
Shev MacNamara, William McLean, Kevin Burrage
Contour integrals in the complex plane are the basis of effective numerical methods for computing matrix functions, such as the matrix exponential and the Mittag-Leffler function.…
Magnus expansions and pseudospectra of Master Equations
Arieh Iserles, Shev MacNamara
New directions in research on master equations are showcased by example. Magnus expansions, time-varying rates, and pseudospectra are highlighted. Exact eigenvalues are found and c…
Error Control for Exponential Integration of the Master Equation
Katharina Kormann, Shev MacNamara
Error estimates for the numerical solution of the master equation are presented. Estimates are based on adjoint methods. We find that a good estimate can often be computed without…
Robustness analysis of spatiotemporal models in the presence of extrinsic fluctuations
Andreas Hellander, Jan Klosa, Per Lötstedt +1
We analyze the governing partial differential equations of a model of pole-to-pole oscillations of the MinD protein in a bacterial cell. The sensitivity to extrinsic noise in the p…
A Local Inverse Formula and a Factorization
Gilbert Strang, Shev MacNamara
When a matrix has a banded inverse there is a remarkable formula that quickly computes that inverse, using only local information in the original matrix. This local inverse formula…
Fractional Euler Limits and Their Applications
Shev MacNamara, Bruce I Henry, William McLean
Generalisations of the classical Euler formula to the setting of fractional calculus are discussed. Compound interest and fractional compound interest serve as motivation. Connecti…