Parallelize NonlinearModelFit

*To*: mathgroup at smc.vnet.net*Subject*: [mg109554] Parallelize NonlinearModelFit*From*: "Dan O'Brien" <obrie425 at umn.edu>*Date*: Wed, 5 May 2010 06:05:07 -0400 (EDT)

Hello everyone, I am running Windows XP 32bit with Mathematica 7.0.1 on a dual core machine (2X 3.0GHz Pentium D) with 2 gigs of RAM. I have 4 data sets of spectroscopic data (intensity vs. frequency data with 1340 data points each) that I am fitting simultaneously with shared parameters as well as parameters unique to an individual data set. I can set it up to float or keep locked any arbitrary number of the parameters, but I usually set it so not more than 10 (sometimes up to 20) params float at a time. Computations can take minutes to hours, thus I have been looking into Mathematica's ability to parallelize computations. I have some functions set up to define the arguements supplied to NonlinearModelFit. Here is the basic order of operations: In[13]:= LaunchKernels[] Out[13]= {KernelObject[1, "local"], KernelObject[2, "local"]} In[14]:= DistributeDefinitions["Global`"]; In[15]:= Parallelize[NonlinearModelFit[d, m, p, {index, \[Omega]}]] Parallelize::nopar1: NonlinearModelFit[d,m,p,{index,\[Omega]}] cannot be parallelized; proceeding with sequential evaluation. >> Here "d" "m", and "p" are formatted corrected for the necessary arguements for NonlinearModelFit (sequential evaluation proceeds without any errors). From the documentation I believe I have set everything necessary to parallelize, and NonlinearModelFit should greatly benefit from parallelization in terms of computational time. Is it just that this function hasn't been set internally by Mathematica to be able to thread its computations? -DanO