xppaut - X Phase plane plus AUTO. Solves many kinds of equations.

xppaut [options] file

This manual page documents briefly the xppaut command. This manual page was written for the Debian distribution because the original program does not have a manual page. Instead, it has documentation in HTML format; see below.

xppaut is a tool for solving * differential equations, * difference equations, * delay equations, * functional equations, * differential-algebraic equation, * boundary value problems, and * stochastic equations.

The code brings together a number of useful algorithms and is extremely portable. All the graphics and interface are written completely in Xlib which explains the somewhat idiosyncratic and primitive widgets interface.

XPP has the capabilities for handling up to 1800 differential equations. * There are over a dozen solvers including several for stiff systems, a solver for integral equations and a symplectic solver. * Up to 10 graphics windows can be visible at once and a variety of color combinations is supported. * PostScript output is supported as well as GIF and animated GIF movies * Post processing is easy and includes the ability to make histograms, FFTs and applying functions to columns of your data. * Equilibria and linear stability as well as one-dimensional invariant sets can be computed. * Nullclines and flow fields aid in the qualitative understanding of two-dimensional models. * Poincare maps and equations on cylinders and tori are also supported. * Some useful averaging theory tricks and various methods for dealing with coupled oscillators are included primarily because that is what I do for a living. * Equations with Dirac delta functions are allowable. * I have added an animation package that allows you to create animated versions of your simulations, such as a little pendulum moving back and forth or lamprey swimming. See toys! for examples. * There is a curve-fitter based on the Marquardt-Levenberg algorithm which lets you fit data points to the solutions to dynamical systems. * It is possible to automatically generate ``movies'' of three-dimensional views of attractors or parametric changes in the attractor as some parameters vary. * Dynamically link to external subroutines

-silent

Runs without the interface - computes solutions and dumps to a file

-xorfix

On some monitors/graphics setups, the exclusive Or with X doesn't quite work right and this fixes it

-convert

Converts old style ODE files (from the DOS program phaseplane) to the much more intuitive new style ODE file

-newseed

Randomizes the random number generator which will often use the same seed

-allwin

Brings XPP up with all the windows visible

-ee

Emulates shortcuts of Evil Empire style (MS)

-setfile <filename>

Loads the set file before starting up

cd to /usr/share/doc/xppaut/examples/ode

run xppaut and select from the menu

See the HTML documentation in /usr/share/doc/xppaut/html/

This manual page was written by Isaac Jones <ijones@syntaxpolice.org>, for the Debian GNU/Linux system (but may be used by others).