xppaut - X Phase plane plus AUTO. Solves many kinds of equations.
Contents
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
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)
Files
Each user can customize the behavior and appearance of Xppaut via the file “$HOME/.xpprc”. Where the
environment variable $HOME points to the user's home directory. On most systems $HOME will already be
set. Each option line in .xpprc begins with the “@” symbol followed by a comma-separated list of
options. Comment lines begin with the “#” symbol and are ignored.
# Example .xpprc file
@ maxstor=50000
@ meth=qualrk,tol=1e-6,atol=1e-6
#Set up a customized look
@ but=quit:fq,bell=1
@ bigfont=lucidasanstypewriter-bold-14,grads=1
# thats it
An list of the extensive options are given below. For complete description of each of these options the
reader is referred to the technical documentation for Xppaut.
ATOL, AUTOEVAL, AUTOVAR, AUTOXMAX, AUTOXMIN, AUTOYMAX, AUTOYMIN, AXES, BACK, BACKCOLOR, BACKIMAGE,
BANDLO, BANDUP, BELL, BIGFONT, BOUND, BUT, COLORMAP, DELAY, DLL_FUN, DLL_LIB, DS, DSMAX, DSMIN, DT,
DTMAX, DTMIN, DWCOLOR, EPSL, EPSS, EPSU, FOLD, FORECOLOR, GRADS, HEIGHT, JAC_EPS, LOGFILE, LT, MAXSTOR,
METH, MWCOLOR, NCOL, NEWT_ITER, NEWT_TOL, NJMP, NMAX, NMESH, NORMMAX, NORMMIN, NPLOT, NPR, NTST, OUT,
OUTPUT, PARMAX, PARMIN, PHI, POIMAP, POIPLN, POISGN, POISTOP, POIVAR, PS_COLOR, PS_FONT, PS_FSIZE, PS_LW,
QUIET, RANGE, RANGEHIGH, RANGELOW, RANGEOLDIC, RANGEOVER, RANGERESET, RANGESTEP, RUNNOW, SEC, SEED,
SMALLFONT, SMC, SPC, STOCH, T0, THETA, TOL, TOR_PER, TOTAL, TRANS, UEC, UMC, UPC, VMAXPTS, WIDTH, XHI,
XLO, XMAX, XMIN, XNC, XP#, YHI, YLO, YMAX, YMIN, YNC, YP#, ZMAX, ZMIN, ZP#,
Help
Note: On typical X Window installations the command xlsfonts lists available fonts. For example, the
following command lists only the available fixed width fonts:
xlsfonts | grep -i -e "typewriter" \
-e "mono" -e "^[0-9]x[0-9]" \
-e "fixed" -e "-c-" -e "-m-" | sort
Note: For a listing of standard hexadecimal colors see <http://en.wikipedia.org/wiki/Web_colors>.
Name
xppaut - X Phase plane plus AUTO. Solves many kinds of equations.
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
-setfilefilename
Loads the set file before starting up
-runnow
Runs ode file immediately upon startup (implied by -silent)
-bigfontfont
Use the big font whose filename is given
-smallfontfont
Use the small font whose filename is given
-parfilefilename
Load parameters from the named file
-outfilefilename
Send output to this file (default is output.dat)
-icfilefilename
Load initial conditions from the named file
-forecolorcolor
Hexadecimal color (e.g. 000000) for foreground
-backcolorcolor
Hexadecimal color (e.g. EDE9E3) for background
-mwcolorcolor
Hexadecimal color (e.g. 808080) for main window
-dwcolorcolor
Hexadecimal color (e.g. FFFFFF) for drawing window
-backimagefilename
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};
-gradsB
Color gradients will (B=1) or will not (B=0) be used
-widthN
Minimum width in pixels of main window
-heightN
Minimum height in pixels of main window
-bellB
System bell on events will (B=1) or will not (B=0) be used
-internsetB
Internal sets will (B=1) or will not (B=0) be run during batch run
-usetsetname
Named internal set will be run during batch run
-rsetsetname
Named internal set will not be run during batch run
-includefilename
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)
-quietB
Verbose log messages will (B=0) or will not be (B=1) written
-logfilefilename
Verbose log messages are written to named file instead of stdout
-anifilefilename
Load animation (.ani) from the named file
Synopsis
xppaut [-silent] [-xorfix] [-convert]
[-newseed] [-ee] [-allwin]
[-white] [-setfilefile] [-runnow]
[-bigfontfont] [-smallfontfont] [-parfilefile]
[-outfilefile] [-icfilefile] [-gradsboolean] [-bellboolean]
[-forecolorcolor] [-backcolorcolor] [-backimageimage]
[-quietboolean] [-logfilefile] [-internsetboolean] [-usetsetname]
[-rsetsetname] [-includefile] [-qics] [-qpars] [-qsets]
[-anifilefile] [file...]
