Welcome to the Model Builder home page!
This is a simple page, mainly setup to show some screen shots. All the interaction
between users and the developer (Me!) should be done through the project page.
There you will also find a more complete description of what the program
is and does.
That said, let see Model Builder in action!
This is the main frame of Model Builder. On the big white text
window, you can enter your ODEs (only their right hand side). Model Builder
uses a notation similar to that of MatLab (tm) in which the state variables
are referred to as y, y, etc. meaning y0(t), y1(t), etc. and ydot,
ydot, etc. meaning dy0/dt, dy1/dt, etc.
The gray text box allows for the input of parameters to be used in the equations.
the parameters should be referred to as p, p, etc. in the equations
(white box). each parameter is calculated from a single-line-expression (e.g.
p=eval(first line), The lines can be as simple as a number or as complex
as to include Python's lambda functions. By now, You have already realized
that these "parameter lines" can be used specify special terms of the main
equations in order to unclog your main equations. More on that in the User
Manual (to be written).
At the equation box we have a system of three (three lines) ODEs (non-autonomous,
by the way) with no parameters defined. On the small white boxes you enter
information such as initial values for the state variables, time values (or
x values if you prefer) to start and the integration, desired step size (the
algorithm uses variable step sizes internally), etc.
you hit the Run button(the first button on the toolbar), you get a nice Gnuplot
output of the y[i](t). The second Button of the toolbar, saves the plot as
a postscript file.
The plot can be edited by pressing the "edit plot" button (the fourth one)
on the main frame's toolbar.
third button of the main frame's toolbar, shows the output in a spread sheet
which can be saved as CSV ASCII file by pressin the button on the top of
Well that's it for version 0.1.0, more is on the way such as tools for stability
analysis, plot against real data sets, etc. Now, go play with the program
and send me your suggestions
and bug reports. Enjoy!
To run Model builder, you have to have installed on your machine the following
These packages are all free software and are available on most platforms making
Model Builder a multi-platform software