naming: natural -> intuitive bo198214 Administrator Posts: 1,616 Threads: 102 Joined: Aug 2007 05/01/2009, 09:06 AM (This post was last modified: 05/01/2009, 09:07 AM by bo198214.) I want to suggest to rename what until now we called "natural slog" to "intuitive slog". I think this is necessary, as "natural" leads to two misinterpretations: Natural numbers: If one extends the term to "natural sexp" and to "natural iteration" then it can be misunderstood to be the superexponential on natural numbers or the iteration for natural numbers Base e: Many people associate base e with the word "natural" like ln = logarithmus naturali So we can then make use of intuitive slog, intuitive sexp and intuitive iteration without fear of misinterpretation. andydude Long Time Fellow Posts: 510 Threads: 44 Joined: Aug 2007 05/01/2009, 07:46 PM bo198214 Wrote:I think this is necessary, as "natural" leads to two misinterpretations True, not to mention the possibility of confusion with natural transformation which could be used in relation to the Carleman matrix, because the Carleman matrix can be viewed as a functor. andydude Long Time Fellow Posts: 510 Threads: 44 Joined: Aug 2007 05/01/2009, 08:06 PM At the same time, I kind of like "natural", but I also dislike ambiguity... so perhaps if we talked about this a year ago, I would instantly change my terminology, but now that we have used the term extensively, I would have to think about it for a long while before changing terminology. I think this problem is quite common. Especially with the 3-argument Ackermann function / hyperoperations which are commonly equated. I think some of this is alleviated with the use of author names, for example, if we were to call it Walker iteration instead. But this is also ambiguous, since Walker discussed 2 methods: a recursive method and a matrix method. I think that both regular iteration and natural/intuitive iteration can be viewed as different techniques for applying matrix iteration in general. Even though the two seem to work well for base-$e^{1/e}$ tetration, I see the two as mutually exclusive (like parabolic and hyperbolic fixed points). So I personally make the distinction as follows:Analytic iteration of f(x) about $x=x_0$ where $x_0$ is a fixed point, is called regular iteration. Analytic iteration of f(x) about $x=x_0$ where $\mathbf{J}(\mathbf{B}[f(x + x_0)] - I)\mathbf{K}$ is invertible (which requires at the very least that $x_0$ is not a fixed point), is called natural/intuitive iteration. Since the points at which each technique works are mutually exclusive, they can be viewed as special techniques for analytic iteration. That is, if anyone can prove they are equivalent when the domains of the continuous iterates overlap! Andrew Robbins bo198214 Administrator Posts: 1,616 Threads: 102 Joined: Aug 2007 05/01/2009, 08:31 PM (This post was last modified: 05/01/2009, 08:34 PM by bo198214.) andydude Wrote:I think that both regular iteration and natural/intuitive iteration can be viewed as different techniques for applying matrix iteration in general. Haha, that would introduce more ambiguity! Matrix iteration would mean matrix power method for me! Which is applicable to fixed points and non-fixed points. If it is applied to fixed points then it is regular iteration. But intuitive iteration ($\operatorname{slog}^{-1}(t+\operatorname{slog}(x))$) is imho not equal to matrix power iteration, at least not a priori. Quote:like parabolic and hyperbolic fixed points Where also it is not quite clear what "hyperbolic" means ($|f'(x_0)|>1$). Is there also an elliptic ($0<|f'(x_0)|<1$)? Quote:Analytic iteration of f(x) about $x=x_0$ where $\mathbf{J}(\mathbf{B}[f(x + x_0)] - I)\mathbf{K}$ is invertible (which requires at the very least that $x_0$ is not a fixed point), is called natural/intuitive iteration. No, analytic iteration means just that the iterates are analytic. It can not presumed uniquely to be intuitive iteration until equality is shown. andydude Long Time Fellow Posts: 510 Threads: 44 Joined: Aug 2007 05/02/2009, 06:51 PM (This post was last modified: 05/02/2009, 06:55 PM by andydude.) What about normal iteration? I could see some slight confusion here, because "normal" has 2 meanings in general: (1) common and (2) perpendicular. I can't see any reason to use the term "perpendicular tetration", so I don't think we have to worry there. Also, it would be easier to switch from natural to normal since they sound similar too. bo198214 Administrator Posts: 1,616 Threads: 102 Joined: Aug 2007 05/02/2009, 07:19 PM (05/02/2009, 06:51 PM)andydude Wrote: What about normal iteration? Is there something problematic with "intuitive"? I think it has the closest meaning to "natural". "Normal" is a usually taken in functional analysis to bring something into a canonic form (e.g. Gram-Schmidt normalization). I dont think it hits the meaning here. I dont know of any properties that make the solution "normal" compared to others. Its just the intuitive way how you solve this infinite equation system that picks one solution « Next Oldest | Next Newest »

 Possibly Related Threads… Thread Author Replies Views Last Post Natural Properties of the Tetra-Euler Number Catullus 6 936 07/01/2022, 08:16 AM Last Post: Catullus Iterated Hyperbolic Sine and Iterated Natural Logarithm Catullus 2 738 06/11/2022, 11:58 AM Last Post: tommy1729 An intuitive idea log*^[n](F(exp*^[n](z0))) tommy1729 0 1,170 03/03/2021, 12:57 AM Last Post: tommy1729 Approximation to half-iterate by high indexed natural iterates (base on ShlThrb) Gottfried 1 3,983 09/09/2019, 10:50 PM Last Post: tommy1729 Natural cyclic superfunction tommy1729 3 7,442 12/08/2015, 12:09 AM Last Post: tommy1729 "Natural boundary", regular tetration, and Abel matrix mike3 9 25,921 06/24/2010, 07:19 AM Last Post: Gottfried differentiation rules for x[4]n, where n is any natural number Base-Acid Tetration 4 10,534 05/26/2009, 07:52 PM Last Post: andydude

Users browsing this thread: 1 Guest(s)