Memory overflow

*To*: mathgroup at smc.vnet.net*Subject*: [mg34030] Memory overflow*From*: dgolber at aol.com (DGolber)*Date*: Sat, 27 Apr 2002 00:56:36 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

I'm using FindMinimum to find a curve of a certain family which best approximates a set of points. FindMinimum varies the parameters of the curve to minimize the sum of squares of the distances from the points to the curve. Each distance from a point to the curve is itself found using FindMinimum. Things are complicated enough that I have Mathematica using the "Don't know the derivatives" form of the minimizing algorithm. There are a lot of parameters (13) and a lot of points (30), and it's slow. But the problem is that after running about 10 minutes (350 MHz PC) the disk starts kloncking. I've interrupted the program, and used MaxMemoryUsed[], and I can see the memory usage growing as the iteration proceeds. When the memory starts getting full, the program starts paging onto the disk. This slows the program down intolerably (besides which I worry about beating the disk to death). My question is: it's not the kind of programming where I expect the memory usage to grow. There's nothing recurvsive going on, that I can see. Is there something in FindMinimum which is recursive? Can I turn it off? What Tools should I use to find out what's happening? Thanks Dave Golber