The Equations-File xxx.f90, or xxx.f, or xxx.c

A source file xxx.f90 containing the Fortran routines FUNC, STPNT, BCND, ICND, FOPT, and PVLS. Here xxx stands for a user-selected name. If any of these routines is irrelevant to the problem then its body need not be completed. Examples are in auto/07p/demos, where, e.g., the file ab/ab.f defines a two-dimensional dynamical system, and the file exp/exp.f defines a boundary value problem. The simplest way to create a new equations-file is to copy an appropriate demo file. For a fully documented equations-file see auto/07p/demos/cusp/cusp.f90 or auto/07p/gui/aut.f. In GUI mode, this file can be directly loaded with the GUI-button Equations/New; see Section 9.2.

The equations-file can either be written in fixed-form (old-style) Fortran (.f), free-form Fortran (.f90) or in C (.c).