Re: Generation of polynomials

*To*: mathgroup at smc.vnet.net*Subject*: [mg113085] Re: Generation of polynomials*From*: Richard Fateman <fateman at cs.berkeley.edu>*Date*: Tue, 12 Oct 2010 13:50:06 -0400 (EDT)*References*: <i915vd$inm$1@smc.vnet.net>

On 10/12/2010 1:24 AM, Andrzej Kozlowski wrote: > "Simplest" is arguable. Performance is measurable. Right. Here is the argument. Are you in a hurry to run the program, or to write the program? (I wrote the program in about 30 seconds, correctly the first time. I was lucky in guessing that Mathematica used the name "Normal"; it is either an example of plagiarism or incredible coincidence.) Why is this important? Do you want a program that can only be read and understood by someone who is steeped in the intricacies of Mathematica mumbo-jumbo? Or would you like an expression that can be understood more easily (and in fact trivially transliterated into other computer algebra systems -- even "normal"), and is, in some sense, nearly 'language' independent? Expanding an expression in a Taylor series in an auxiliary variable in order to facilitate truncation on a total degree is such a common kind of idea that other systems have it built in to their expansion routines for multivariate series. I view it as a defect in Series (and have, I think, mentioned it) that total degree truncation of a multivariate series is not provided in Mathematica. If it were, one could simply write Series [Product[...],{x,y},{0,0},n] where n is total degree. RJF > >