Published on *Computer Science Department at Princeton University* (http://www.cs.princeton.edu)

The paper describes a smart interface that makes numerical libraries

easy to use and reliable by exploiting mathematical theory, symbolic

algebra, and descriptions of the input/output formats of numerical

subroutines. The interface accepts a high-level problem description,

selects the appropriate numerical subroutine, programs the problem in

subroutine format, runs the program, corrects for numerical errors and

special conditions, and returns the output in a high-level format. The

current interface manages a root finder, a continuation package, an

ordinary differential equation integrator, and a Lyapunov exponent

calculator. I describe these functions and illustrate their use in a

program that analyzes ordinary differential equations.