CLUTCH - an ordinary differential equation solver for initial value problems

Abstract

A description is given of a computer package which provides a simple interface to the LSODE (ordinary differential equation solving) subroutines developed at Lawrence Livermore Laboratory. Standardized input and output procedures help users to obtain numerical solutions to initial value problems with minimal effort. As well as providing data for a problem, the user need only provide the source for a single FORTRAN subroutine which calculates the first derivatives of the problem's dependent variables. The package can operate in batch and interactive modes and the numerical results can be displayed either as tables or graphs by using a set of simple English Language commands.