Discrete Ill-posed Problems

On the following page is an applet demonstrating different regularization methods, to solve Ill-posed discrete problems. The applet is divided into two parts: On the first page you can setup the model-problem, and on the second page you can try the different methods to see which gives the best result.

The lower graph on page 1, and the upper on page 2, can show other parts of the model. This options can be acessed by rightclicking, (or holding down the META- key and leftclicking) on those graphs. The 3d-Graphs are unavailable if there is more 64 interpolation points.

If you run the applet with many interpolation points (>512) the browser may run out of memory, if you use one the SVD-based methods.

The applet requires at least Java 1.2 to work properly. If you don't have Java 1. 2 or higher, it can be downloaded from here:
http://java.sun.com

Most of the matrix-operations are done with Jama. For more information see:
http://math.nist.gov/javanumerics/jama

The examples are taken from "Rank Deficient and Discrete Ill-Posed Problems" - Per Christian Hansen.

Jens Hvelplund, c973650 (at) student . dtu . dk