IFS D.E.

The function you see to the right was created with IFS D.E.* Click here or click the logo above for a test drive! What is IFS D.E.? How do you use IFS D.E.? IFS D.E. is free software. Download it at Sourceforge! © 2007 Leon Q. Brin * The data points of the function were created with IFS D.E.  The plots were created with OpenOffice.org, a free office suite.  Dowload it and you can view the spreadsheet.

lift function data

What is IFS D.E.?

IFS D.E. is a program for generating smooth lift functions like the one you see above.  Though you don't need to know it in order to use the program, the functions it produces are actually iterated function system (IFS) attractors which solve self-referential ODEs.  That's where it gets the "IFS" part of its name. 

How do you use IFS D.E.?

1. Basic Usage
1. Tools and buttons
2. The function
2. The Equations
1. Velocity Type
2. Acceleration Type

1. Basic usage

a. Tools and buttons

When the applet starts up, you should see a gridded design area. That grid is where you will design your function. No time like the present to experiment a little. Click and drag one of the circles on the x-axis, and watch the preview change.

Clicking the "Reset Parameters" button returns the default design. It's sort of a "start over" button.

Clicking the "Acceleration Type" button switches to a design with four parameters (and changes the button to "Velocity Type"). Clicking the "Velocity Type" button switches to a design with two parameters (and changes the button to "Acceleration Type").

Clicking the "Symmetric" button makes the circle tools remain symmetric about 0.5 as they are dragged about (and changes the button to "Asymmetric"). Clicking the "Asymmetric" button allows the circles to be manipulated independently.

b. The Function

2. The Equations

a. Velocity Type

The velocity type functions are solutions of the ODE

b. Acceleration Type

The acceleration type functions are solutions of the ODE