Slideshow -- selected still-images (gif), about 10kB each.

Still images w/ some text from 4th ICTMT, Plymouth 1999.


Flyer for October 1999 Colloquium.
Try out the Vector Field Analyzer.
Download the Java Microscope.(microscope.zip) (version from Fall 1999). 
To run the program, first unzip the file (e.g. when using WinZip "Be sure the Use Folder Names checkbox is checked" when extracting), then load "index.html" into any JAVA compliant web browser. The zip file contains all of the files required to run Java Vector Field Analyzer as well as the source code for David Wanqain Liu's parser and some of the GUI components from Symantectm.
This is the home-page of the OLD Vector Field Analyzer which has been superseded by the Vector Field Analyzer II The new one is written entirely in JAVA 2 (but w/o Swing or Graphics2d). You may still run the old vector field analyzer. All you need is a JAVA-1 enabled browser (and either an internet connection, or you may download the vf-analyzer once for all). A full workbook with many explorations to accompany the software is nearing completion -- please contact me if you are interested in reviewing/class-testing the manuscript .....

Expect a few more changes in the vector field analyzer in coming weeks.
Bookmark this site for an up-to-date preliminary version.

This work has been supported in part by the National Science Foundation through the award DUE 97-52453 and the Foundation Coalition.

There are two main parts to the vector field ANALYZER. The first part helps visualize the derivatives (and their principal geometric components) by simple zooming -- just as easy as in the calculus of functions of a single variable -- after sufficient magnification you obtain linear vector fields, i.e. the Jacobian, the curl, the divergence etc.

The vector field analyzer is fully interactive -- drag the lens to any point and change the magnification factor. Several important fields are predefined, or enter any formula (the analyzer comes with a powerful parser....) Challenge: Take a look and SEE that the derivative of the flow past a cylinder has (OBVIOUS) winding number 3/2!
The screen-shot clearly shows that the magnetic field Im(dz/z) is divergence free and irrotational!

The differential part of the analyzer is complemented by interactive tools to explore and study the integral aspects of vector fields: The main innovation allows for interactive explorations of the nonlinear flow, of the linearized flow, and of the flows of the principal geometric components of the linearized flow. To visualize these define (draw!) your own regions and follow their evolution -- e.g. see that the exponential of a linear map is linear (preserves polygonal character), see orthogonality, and area-preservation at work and discover a whole new world of exciting links between vector calculus, differential equations, linear algebra and baby-Lie groups.
The screen shot shows part of a live animation of the area-preserving flow associated to the magentic field Im(dz/z).