Dear Rolf, I join this discussion a little bit late.
Indeed, the '**' operator is a very poor choice for exponentiation. I can give some examples to justify my claim. Notice that '**' and '*' would almost always get mixed in real mathematics. Fortunately, I am used to "^"; otherwise, I would have had a very hard time to debug the *monster*: https://github.com/discoleo/R/blob/master/Math/Poly.System.S5.Ht.Formulas.Derivation.Coeffs.R Those are the coefficients of a polynomial of order 7 (see below for further information). And I have plenty of examples. Unfortunately, some "programming" languages mix '*' and '**'; which makes any work with polynomials a nightmare! I "found" something on this topic - hope everyone gets a little bit amused: https://github.com/discoleo/R/blob/master/Math.NewTerminology.wiki Sincerely, Leonard =========== Regarding the *Monster*: It enables to solve a particular system with 5 variables with cyclic symmetry: x1+x2+x3+x4+x5 = R1 # Note: this is NOT the full E2 x1*x2+x2*x3+x3*x4+x4*x5+x5*x1 = R2 E3 = R3 E4 = R4 E5 (= x1*x2*x3*x4*x5) = R5; This system can be transformed into a system that can be solved using a polynomial of lower order than the original system. Unfortunately, I do not have a methemtical theory yet for the Ht5 System. I worked it out the hard way; it is almost finished, but I did not have any more time during the last 2 years. For some (very) basic details, see: https://github.com/discoleo/R/blob/master/Math/Poly.System.md Again, I did not have time to write anything more thoroughly. [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide https://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
