Avoid the use of certain functions
in [Mathematica]
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From: Sam Takoy on 17 Jul 2010 08:16 Hi, Is there a way to ask Mathematica to avoid expressing answers in terms of certain functions. For example, I can stand Sec, Csc, Sech, and Csch and would rather see Sec^-1, etc. Thanks!
From: Murray Eisenberg on 18 Jul 2010 01:02 I don't think I understand your question, given that Sec^-1 means ArcSec. Which are you trying to avoid, ArcSec or hyperbolic functions Sech, etc.? If you're just trying to avoid hyperbolic functions, you could use TrigToExp, e.g.: TrigToExp[Sech[x]] // InputForm 2/(E^(-x) + E^x) [For purposes of text messages in this newsgroup, I used InputForm there just in order to produce a 1-dimensional output instead of an actual 2-dimensional built-up (compound) fraction.] Similary: TrigToExp[ArcSech[x]] Log[Sqrt[-1 + x^(-1)]*Sqrt[1 + x^(-1)] + x^(-1)] On 7/17/2010 8:16 AM, Sam Takoy wrote: > Hi, > > Is there a way to ask Mathematica to avoid expressing answers in terms > of certain functions. For example, I can stand Sec, Csc, Sech, and Csch > and would rather see Sec^-1, etc. > > Thanks! > -- Murray Eisenberg murray(a)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
From: David Park on 18 Jul 2010 01:02 You could always do something like this: MakeBoxes[Csc[x_], form : (StandardForm | TraditionalForm)] := InterpretationBox[#1, #2] & @@ {MakeBoxes[HoldForm[1/Sin[x]]], Csc[x]} 1/Sin[x] % // FullForm Use MakeBoxes[Csc[x_], form : (StandardForm | TraditionalForm)] =. to clear the definition. Frankly, I wouldn't do that kind of formatting because it is too special and is hiding what Mathematica is actually working on and may not give the intended result with more complicated expressions. Clearly, you are trying to use Mathematica in a way that gives clearer results in a textbook form. This is a good idea. If you gave some specific examples you might obtain better answers. David Park djmpark(a)comcast.net http://home.comcast.net/~djmpark/ From: Sam Takoy [mailto:sam.takoy(a)yahoo.com] Hi, Is there a way to ask Mathematica to avoid expressing answers in terms of certain functions. For example, I can stand Sec, Csc, Sech, and Csch and would rather see Sec^-1, etc. Thanks!
From: AES on 19 Jul 2010 02:10 > From: Sam Takoy [mailto:sam.takoy(a)yahoo.com] > > Hi, > > Is there a way to ask Mathematica to avoid expressing answers in terms > of certain functions. For example, I [can't?] stand Sec, Csc, Sech, and Csch > and would rather see Sec^-1, etc. I'm with you on this one: always hated Sec and Csc (and never understood the backward naming of these functions -- why isn't Sec = 1/Sin and Csc = 1/Cos?) So, I'd like the various Simplifiy and XxxToYyy functions in Mathematica to always give precedence to Sin and Cos by default, and avoid using Sec and Csc whenever possible, even if this produces some "1 overs" in the output expression. But I suspect trying to implement this at this point would require more complexity than it would be worth.
From: Andrzej Kozlowski on 20 Jul 2010 03:43
On 19 Jul 2010, at 08:10, AES wrote: >> From: Sam Takoy [mailto:sam.takoy(a)yahoo.com] >> >> Hi, >> >> Is there a way to ask Mathematica to avoid expressing answers in terms >> of certain functions. For example, I [can't?] stand Sec, Csc, Sech, and Csch >> and would rather see Sec^-1, etc. > > I'm with you on this one: always hated Sec and Csc (and never > understood the backward naming of these functions -- why isn't Sec == > 1/Sin and Csc == 1/Cos?) Have you never noticed this: 1+ Tan[x]^2====Sec[x]^2 1+Cot[x]^2====Csc[x]^2 ? Andrzej Kozlowski |