Documentation

If you want to modify the demonstrations beyond changing the parameters displayed you must download the executable PDE.jar and load a suitably modified HTML file (e.g. Test.html) into your browser or the java appletviewer. The following parameters can be set by editing the HTML file:

Parameter	Function	Default value	Notes
function	Equation solved	0	See below
parameter0	1st parameter of equations	Set in java file
parameter1	2nd parameter of equations	Set in java file
...	... parameter of equations	Set in java file	Number of parameters set in java file
solvewidth	Number of mesh points in x	64	Must be 2ⁿ
solveheight	Number of mesh points in y	64	Must be 2ⁿ
dt	Time step in solver	0.51
mesh	Mesh size	1.
ic00	1st initial condition parameter	Set in java file	See below
ic01	2nd initial condition parameter	Set in java file	See below
plotwidth	Size of plot in x	256
plotheight	Size of plot in y	256
chooseplots	Shows "Plot Type"	true
plottype	Initial Plot Type	0
plotFFT	Plots FFT	true	Only applies for spectral evolution
pallette	Pallette	0	If nonzero sets pallette, otherwise got from java file
scaleplot	Allows plot to rescale with window	false	Only useful with appletviewer
scaleminmax	Scales color plot with min/max values	true
showminmax	Shows values of min/max	true
minimum	Minimum value of color scale	0	Only used if scaleMinMax=false
maximum	Maximum value of color scale	1	Only used if scaleMinMax=false
showtime	Shows time of evolution	true
speed	Sets initial speed	1

Any parameter that is absent in the HTML file is given the default value.

Various equations can be solved. The following table gives the equation and the corresponding java files where the evolution, default parameter, initial conditions, etc. are defined. You can add your own function using these examples as templates.

Number	Equation	Java File
0	Complex Ginzburg Landau	CGL
1	Brusselator	Brusselator
2	Schnackenberg	Schnackenberg
3	Swift-Hohenberg	SH
4	Barkley	Barkley
5	Bar-Eiswirth	Bar
6	Lifshitz-Petrich	Lifshitz
7	2 Coupled Swift-Hohenberg	SH2
8	FitzHugh-Nagumo	FHN

The initial conditions are set in the equation java files taking parameters from the HTML file. The parameter ic00 gives the value of the first parameter in the initial condition function of the first equation, ic01 gives the value of the second parameter in the initial condition function of the first equation, ic10 gives the value of the first parameter in the initial condition function of the second equation, etc. The number of initial condition parameters required is set in the java file.

The java source code is here.