Debugging

Replace the call to sd() in your ``sch.m'' script file with lm(), and run. If you have implemented steepest descents correctly, you should find that the energy always decreases and that the angle cosine test gives nearly zero, indicating that the new gradient is orthogonal to the previous search direction. Note that at the start, when you are far from the minimum and the function is not very quadratic, the approximate minimization is not perfect and you may see angle cosines near 0.1. However, after about 20 iterations, the algorithm begins to approach the minimum, and the angle cosines will become much smaller ($\sim 10^{-4}$) and continue to improve as the minimization proceeds.



Tomas Arias 2004-05-04