Bethany Nicholson

An implicit function formulation for optimization of discretized index-1 differential algebraic systems

  • Robert Parker
  • Bethany Nicholson
  • John D. Siirola
  • Carl D. Laird
  • Lorenz T. Biegler
    • Categories Systems governed by Differential Equations Optimization Tags , , ,

    A formulation for the optimization of index-1 differential algebraic equation systems (DAEs) that uses implicit functions to remove algebraic variables and equations from the optimization problem is described. The formulation uses the implicit function theorem to calculate derivatives of functions that remain in the optimization problem in terms of a reduced space of variables, allowing … Read more

    Scalable Parallel Nonlinear Optimization with PyNumero and Parapint

  • Jose Rodriguez
  • Robert Parker
  • Carl D. Laird
  • Bethany Nicholson
  • John D. Siirola
  • Michael Lee Bynum
    • Categories Nonlinear Optimization, Parallel Algorithms Tags ,

    We describe PyNumero, an open-source, object-oriented programming framework in Python that supports rapid development of performant parallel algorithms for structured nonlinear programming problems (NLP’s) using the Message Passing Interface (MPI). PyNumero provides three fundamental building blocks for developing NLP algorithms: a fast interface for calculating first and second derivatives with the AMPL Solver Library (ASL), … Read more

    pyomo.dae: A Modeling and Automatic Discretization Framework for Optimization with Differential and Algebraic Equations

  • Lorenz T. Biegler
  • Jean-Paul Watson
  • Victor M. Zavala
  • Bethany Nicholson
  • John D. Siirola
    • Categories Modeling Languages and Systems, Optimization of Systems modeled by PDEs, Systems governed by Differential Equations Optimization Tags , , , ,

    We describe pyomo.dae, an open source Python-based modeling framework that enables high-level abstract specification of optimization problems with differential and algebraic equations. The pyomo.dae framework is integrated with the Pyomo open source algebraic modeling language, and is available at http: //www.pyomo.org. One key feature of pyomo.dae is that it does not restrict users to standard, … Read more