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