Re: Re: Re: Re: Re: Log[x]//TraditionalForm

*To*: mathgroup at smc.vnet.net*Subject*: [mg96186] Re: [mg96160] Re: [mg96144] Re: [mg96120] Re: [mg96062] Re: [mg96049] Log[x]//TraditionalForm*From*: Andrzej Kozlowski <akoz at mimuw.edu.pl>*Date*: Mon, 9 Feb 2009 05:31:37 -0500 (EST)*References*: <200902031132.GAA00303@smc.vnet.net> <200902050941.EAA10589@smc.vnet.net> <200902060914.EAA03215@smc.vnet.net> <200902070838.DAA24272@smc.vnet.net>

Of course what Murray meant by "advanced" meant "advanced mathematics". ( I myself wrote "aimed at mathematicians"). I think most people will agree that physics is "what physicist do" and engineering is "what engineers do" so presumably mathematics is what mathematicians do. (Others might use it but they do not normally *do* it, with the exception of a few "borderline cases", most notably Edward Witten). And Murray's (and mine) point was that in advanced books meant for mathematicians the notation ln is (almost) never used, which of course does not mean that it isn't used in very advanced texts in physics etc. There are several reasons why mathematicians do not like the notation ln. One is that in text on analysis the only logarithms ever considered are the "natural" ones. As there is no need for any other logarithms there is no need for any special notation for "natural logarithms" (they are the only ones). Moreover, the usual one dimensional logarithm is only a special case of the inverse of the exponential map in the theory of Lie Groups (or even manifolds with connection) and these logarithms do not involve any basis and nobody, not even physicists writes ln for the inverse of the general exponential map. Someone the same thread suggested that the "criterion" for an "advanced book" should be whether it uses the notation log or ln, and probably thought himself very witty. However, this immediately brought to my mind a very famous story, which played a big role in the history of mathematics and which has a lot to do with this issue Just a few days after the unexpected death of his father, Galois took the the entrance examination to the =C9cole Polytechnique for the second time. It became a legend in the history of mathematics. He was aware that a refusal would be final this time, if he would flunk again. The examiners, though being recognized mathematicians, were not capable of detecting the mathematical genius of Evariste Galois. One of the two examiners asked the fatal question: He should describe the theory of the arithmetic logarithms. Galois criticized immediately the question, and mentioned to professor Dinet that there are no arithmetic logarithms. Why didn't he simply ask for the theory of the logarithms? Thereupon Galois refused to explain some propositions concerning logarithms. He said that it was completely obvious! This was apparently the dot on the i: He failed the examination. (Quoted from http://www.galois-group.net/g/EN/fate.html) Evariste Galois was certainly a very "advanced" mathematician. His examiner Charles Louis Dinet, in the words of the historian E.T. Bell, was =93not worthy enough to sharpen his (Galois) pencil=94. Andrzej Kozlowski On 7 Feb 2009, at 08:38, Curtis Osterhoudt wrote: > =46rom what I've seen, (most of) the physics books published > recently (and going so far back as 1953, though Morse & Feshbach's > _Methods_of_Theoretical_Physics_ was "renewed" --- whatever that > means --- in 1981) have the "ln" notation, rather than "log". This > is pretty much true across the spectrum, from optics to acoustics to > math methods to GR to fluid mechanics to classical dynamics and > electrodynamics, and so forth. It's also true at all levels, from > undergraduate texts to very specialized texts. In that respect, > there's no "more advanced course" to go on to, unless it's more > associated with maths in the stead of physics. Maybe we're still to > attached to our Napier's Bones. > > Once one is in the field, it should almost always be obvious from > context what base logarithm is being used, unless (and this one is a > large pet peeve of mine) the authors are inconsistent, or mix > notation. Students have no call to be confused by such little > things :) > > C.O. > > > > > On Friday 06 February 2009 02:14:24 am Murray Eisenberg wrote: >> So far as I have seen, almost any recently published, high-selling >> textbook in calculus -- as distinct from advanced calculus or >> analysis >> -- aimed at the U.S. market uses ln rather than log for the natural >> logarithm. >> >> No wonder students are confused when they go on to a more advanced >> course and suddenly it's log, not ln. >> >> Then of course there's the issue that computer scientists often use >> log >> to mean base-2 log. >> >> Andrzej Kozlowski wrote: >>> Tthe notation ln seems to have become essentially extinct since the >>> disappearance of slide rules. It fact, was almost never used in >>> books >>> on analysis or calculus aimed at mathematicians. I have just >>> checked and >>> Dieudonne, Foundations of Modern Analysis, published in 1969 uses >>> log, >>> Apostol, Calculus, published in 1967 uses log, Rudin, "Principles of >>> Modern Analysis", published in 1964 uses L after remarking that "the >>> usual notation is, of corse, log"), Rudin "Real and complex >>> analysis", >>> published in 1970 uses (naturally) log. Of 5 books that I have >>> looked >>> at only one, Fichtenholtz - A course of differential and integral >>> calculus (in Russian) published in 1966 uses ln, which is presumably >>> because it was aimed at engineers, who in those days still used >>> slide >>> rules (at least in Russia). (In spite of that, it is still a rather >>> good book). >>> >>> Andrzej Kozlowski >>> >>> >>> On 4 Feb 2009, at 11:18, Murray Eisenberg wrote: >>> >>>> No, in mathematics log x or log(x) is a perfectly acceptable, >>>> perhaps >>>> the predominant, notation for the base-e, natural logarithm. >>>> >>>> In calculus books, ln x or ln(x) is typically used for that -- >>>> so as >>>> not to confuse students who were taught that log means the base-10 >>>> logarithm. >>>> >>>> O.T.: P.S. M.I.T. has an all-male a cappella singing group named >>>> the >>>> "Logarhythms". >>>> >>>> slawek wrote: >>>>> The natural logarithm function in "traditional form" in >>>>> Mathematica >>>>> (version >>>>> 6.0.2.0) >>>>> >>>>> Log[x]//TraditionalForm >>>>> log(x) >>>>> >>>>> This is "not a bug but a feature", but in mathematics the natural >>>>> logarithm >>>>> is just ln(x) or even ln x. >>>>> The true traditional notation use log for decimal logarithm, ln >>>>> for >>>>> natural >>>>> logarithm, lb for binary logarithm, and >>>>> log_{b}x for logarithm with base b. Unfortunatelly in most >>>>> computer >>>>> programs (see FORTRAN) LOG >>>>> stands for natural logarithm (an exception is Pascal). >>>>> >>>>> Nevertheless, how to force to use ln(x) instead log(x) ? >>>>> >>>>> The brute way is use /.Log->ln//TraditionalForm. >>>>> >>>>> Is any more elegant way to do this? >>>>> >>>>> slawek >>>>> >>>>> >>>> -- >>>> Murray Eisenberg murray at math.umass.edu >>>> Mathematics & Statistics Dept. >>>> Lederle Graduate Research Tower phone 413 549-1020 (H) >>>> University of Massachusetts 413 545-2859 (W) >>>> 710 North Pleasant Street fax 413 545-1801 >>>> Amherst, MA 01003-9305 >>>> >>> >>> >> > > > > -- > ========================= ========================== ========= > Curtis Osterhoudt > cfo at remove_this.lanl.and_this.gov > PGP Key ID: 0x4DCA2A10 > Please avoid sending me Word or PowerPoint attachments > See http://www.gnu.org/philosophy/no-word-attachments.html > ========================= ========================== ========= >

**References**:**Log[x]//TraditionalForm***From:*"slawek" <human@site.pl>

**Re: Re: Log[x]//TraditionalForm***From:*Andrzej Kozlowski <akoz@mimuw.edu.pl>

**Re: Re: Re: Log[x]//TraditionalForm***From:*Murray Eisenberg <murray@math.umass.edu>

**Re: Re: Re: Re: Log[x]//TraditionalForm***From:*Curtis Osterhoudt <cfo@lanl.gov>