xppaut - Online in the Cloud

PROGRAM:

NAME

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

SYNOPSIS

xppaut [-silent] [-xorfix] [-convert]
[-newseed] [-ee] [-allwin]
[-white] [-setfile file] [-runnow]
[-bigfont font] [-smallfont font] [-parfile file]
[-outfile file] [-icfile file] [-grads boolean] [-bell boolean]
[-forecolor color] [-backcolor color] [-backimage image]
[-quiet boolean] [-logfile file] [-internset boolean] [-uset setname]
[-rset setname] [-include file] [-qics] [-qpars] [-qsets]
[-anifile file] [file...]

DESCRIPTION

xppaut is a tool for solving:

· differential equations
· difference equations
· delay equations
· functional equations
· differential-algebraic equation
· boundary value problems
· stochastic equations

The code brings together a number of useful algorithms and is written in C. All the
graphics and interface are created using the X Window System protocol client library Xlib
<http://www.xfree86.org>.

xppaut capabilities:
· Handles up to 1950 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 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
· Equations with Dirac delta functions are allowable
· Animations of simulations such as a little pendulum moving back and forth or lamprey
swimming
· A curve-fitter based on the Marquardt-Levenberg algorithm which lets you fit dynamical
systems to data
· Generate "movies" of three-dimensional views of attractors or parametric changes in
the attractor as some parameters vary
· Dynamically link to external subroutines
· From the command line type /dev/stdin as the file and you can write the ODE on the fly

OPTIONS

-silent
Batch run without the interface and dump solutions to a file

-xorfix
Work-around for exclusive Or with X on some monitors/graphics setups

-convert
Convert old style ODE files (e.g. phaseplane) to new ODE style

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

-ee
Emulates shortcuts of Evil Empire style (MS)

-allwin
Brings XPP up with all the windows visible

-white
Swaps foreground and background colors

-setfile filename
Loads the set file before starting up

-runnow
Runs ode file immediately upon startup (implied by -silent)

-bigfont font
Use the big font whose filename is given

-smallfont font
Use the small font whose filename is given

-parfile filename
Load parameters from the named file

-outfile filename
Send output to this file (default is output.dat)

-icfile filename
Load initial conditions from the named file

-forecolor color
Hexadecimal color (e.g. 000000) for foreground

-backcolor color
Hexadecimal color (e.g. EDE9E3) for background

-mwcolor color
Hexadecimal color (e.g. 808080) for main window

-dwcolor color
Hexadecimal color (e.g. FFFFFF) for drawing window

-backimage filename
Name of bitmap file (.xbm) to tile in background

For example, the following text saved to a file named stipple2.xbm can be loaded to
impart a stippled background.

#define stipple2_width 2
#define stipple2_height 2
static char stipple2_bits[] = {
0x02,0x01};
-grads B
Color gradients will (B=1) or will not (B=0) be used

-width N
Minimum width in pixels of main window

-height N
Minimum height in pixels of main window

-bell B
System bell on events will (B=1) or will not (B=0) be used

-internset B
Internal sets will (B=1) or will not (B=0) be run during batch run

-uset setname
Named internal set will be run during batch run

-rset setname
Named internal set will not be run during batch run

-include filename
Named file will be included (see include directive)

-qsets
Query internal sets (output saved to OUTFILE)

-qpars
Query parameters (output saved to OUTFILE)

-qics
Query initial conditions (output saved to OUTFILE)

-quiet B
Verbose log messages will (B=0) or will not be (B=1) written

-logfile filename
Verbose log messages are written to named file instead of stdout

-anifile filename
Load animation (.ani) from the named file

ENVIRONMENT

XPPSTART
File browser will open to the specified path. This may be useful in an
instructional setting to point to a mapped drive containing course materials.

XPPHELP
Path to the XPPAUT documentation file <xpphelp.html> (e.g.
/usr/share/doc/xppaut/html/xpphelp.html)

XPPBROWSER
Web browser to view documentation (e.g. /usr/bin/firefox)

Use xppaut online using onworks.net services