From cayuga.cs.vt.edu!ltw Mon Jul 22 18:59:20 0400 1991 Date: Mon, 22 Jul 91 18:59:20 -0400 From: ltw@cayuga.cs.vt.edu (Layne Watson) To: ehg@research.att.com Subject: 0DOC.for C C HOMPACK is a suite of FORTRAN 77 subroutines for solving nonlinear C systems of equations by homotopy methods. There are subroutines for C fixed point, zero finding, and general homotopy curve tracking problems, C utilizing both dense and sparse Jacobian matrices, and implementing C three different algorithms: ODE-based, normal flow, and augmented C Jacobian. The (driver) subroutines called by the user are given in the C table below, and are well documented internally. The user need not C be concerned with any other subroutines in HOMPACK. C C C Problem type C --------|--------|--------|--------|--------|--------| C x = f(x) | F(x) = 0 |rho(a,lambda,x)=0| C --------|--------|--------|--------|--------|--------| C dense | sparse | dense | sparse | dense | sparse | Algorithm C --------|--------|--------|--------|--------|--------|--------------------- C FIXPDF | FIXPDS | FIXPDF | FIXPDS | FIXPDF | FIXPDS | ODE based C --------|--------|--------|--------|--------|--------|--------------------- C FIXPNF | FIXPNS | FIXPNF | FIXPNS | FIXPNF | FIXPNS | normal flow C --------|--------|--------|--------|--------|--------|--------------------- C FIXPQF | FIXPQS | FIXPQF | FIXPQS | FIXPQF | FIXPQS | augmented Jacobian C --------|--------|--------|--------|--------|--------|--------------------- C C C The sparse subroutines use the packed skyline storage scheme standard in C structural mechanics, but any sparse storage scheme can be used by C replacing some of the low-level HOMPACK routines with user-written C routines. The stepping subroutines STEP?? may be of interest to some C users with special curve tracking needs. C C C * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * C C * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * C