BB: An R Package for Solving a Large System of Nonlinear Equations and for Optimizing a High-Dimensional Nonlinear Objective Function

• Main Authors: Ravi Varadhan, Paul Gilbert
• Format: Article
• Language: English
• Published: Foundation for Open Access Statistics 2009-10-01
• Series: Journal of Statistical Software
• Subjects: accelerate failure time model; Barzilai-Borwein; derivative-free; estimating equations; large-scale optimization; non-monotone line search; non-smooth optimization; rank- based regression
• Online Access: http://www.jstatsoft.org/v32/i04/paper

We discuss <code>R</code> package <b>BB</b>, in particular, its capabilities for solving a nonlinear system of equations. The function <code>BBsolve</code> in <b>BB</b> can be used for this purpose. We demonstrate the utility of these functions for solving: (a) large systems of nonlinear equations, (b) smooth, nonlinear estimating equations in statistical modeling, and (c) non-smooth estimating equations arising in rank-based regression modeling of censored failure time data. The function <code>BBoptim</code> can be used to solve smooth, box-constrained optimization problems. A main strength of <b>BB</b> is that, due to its low memory and storage requirements, it is ideally suited for solving high-dimensional problems with thousands of variables.