Re: Need for (FindFit, Refine) ?
- To: mathgroup at smc.vnet.net
- Subject: [mg42466] Re: [mg42456] Need for (FindFit, Refine) ?
- From: Sseziwa Mukasa <mukasa at jeol.com>
- Date: Thu, 10 Jul 2003 03:36:50 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
On Wednesday, July 9, 2003, at 08:24 AM, Ersek, Ted R wrote: > Hello, > > In Mathematica version 5 we have new functions FindFit, and Refine. > > Why do we need FindFit when we already had Fit? See http://wolfram.com/products/mathematica/newin5/numeric/findfit.html. > What can we do with Refine that we couldn't previously do with > Simplify or > FullSimplify? Try duplicating the example of Refine given here http://wolfram.com/products/mathematica/newin5/symbolic/assuming.html with Simplify or FullSimplify in version 4.2. Whether this is useful or not is a different question. I think the Assumptions function could simplify some programs. > Why? At the NKS2003 conference there was a short session on the new features in version 5. It was stated that the primary purpose of version 5 was to improve Mathematica's numeric capabilities, hence FindFit. There were several impressive demonstrations of what can be done with the StepMonitor and EvaluationMonitor options. I cannot really speak for Refine, but many of the new functions are definitely superior to their older counterparts. > (1) A Mathematica with 3000 functions is harder to master than one > with 1500 > functions (or at least it seems that way to a beginner). The older function names could have been retained, but then you'd have 1500 functions each of which has 4 new optional parameters. I suppose it's a matter of taste whether you want to add options to existing function names or add new functions. In the case of FindFit at least, two functions Fit and NonlinearFit have actually been superseded by one function. Of course it is necessary to retain the old names for legacy code. As for beginners, I find the biggest difficulty, whether one is a beginner or not, is determining which function out of a family is appropriate to the problem at hand to begin with. Once one candidate is found, the See Also section of the Help Browser is usually sufficient to explore related functions and identify the optimal candidate. For example using Select or Sow and Reap will require some experimentation with a variety of programs. I assume in version 5, which I do not have yet, that Sow and Reap will show up in the See Also section for Select. > (2) Increasing the number of symbols increases the chance of problems > due to > shadowed symbols. Can't argue with that, although following the lower case convention for user defined symbols makes this a moot point. Regards, Sseziwa