Re: Re: Overriding Power

*To*: mathgroup at smc.vnet.net*Subject*: [mg26965] Re: [mg26868] Re: Overriding Power*From*: Jeff Hersh <frumple*NOSPAM* at home.com>*Date*: Tue, 30 Jan 2001 03:38:17 -0500 (EST)*References*: <94m9e5$3nu@smc.vnet.net> <94oh4k$ee1@smc.vnet.net> <200101260627.BAA18659@smc.vnet.net> <6SJc6.6841$nn4.184149@ralph.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Carl, The problem is that I am trying to mimic the standard notation that is used for Geometric Algebra. The precedence is as follows... Outer Products (designated by \[Wedge]) Inner Products (designated by \[Dot]) Commutator and Scalar Products (designated by \[CircleTimes] and \[CircleDot] respectfully). Geometric Product (designated by white space, i.e. \[Times]). I know you can force different parethesiation via PrecedeceForm for individual items but this doesn't seem to work in general. Jeff In article <6SJc6.6841$nn4.184149 at ralph.vnet.net>, Carl Woll <carlw at u.washington.edu> wrote: > Jeff, > > I don't know how to change the precedence of a function, but why don't > you use > a built in operator which already has the precedence you want. For > example, if > you want to have a function whose precedence is greater than > NonCommutativeMultiply, you could look up in help for precedence, which > will > lead you to section A.2.7. Section A.2.7 contains a list of the > precedences of > all the built in operators. You will see that there are two built in > operators, > SmallCircle and CircleDot which carry a higher precedence than > NonCommutativeMultiply and which have no built in definitions. Hence, we > have > > a**b\[SmallCircle]c//FullForm > > NonCommutativeMultiply[a, SmallCircle[b, c]] > > Since SmallCircle has no built in definitions, simply give it the > definitions > you want. > > Carl Woll > Physics Dept > U of Washington > > Jeff Hersh wrote: > > > In article <94oh4k$ee1 at smc.vnet.net>, Roland Franzius > > <Roland.Franzius at uos.de> wrote: > > > > > Jeff Hersh wrote: > > > > > > > I am working on a package that deals with non-communative > > > > multiplication > > > > and I have run into a problem with the Power function. As we know > > > > Power[a b,n] (where n is an integer) automatically gets converted > > > > to > > > > Power[a,n] Power[b,n]. However, with non-communative multiplication > > > > (I > > > > have removed the Orderless attribute from Times to make it > > > > non-communative) this isn't valid. Is there any way I can stop > > > > Mathematica from automatically doing this conversion? > > > > > > Hi Jeff, > > > I recommend to avoid overloading the existing algebraic functions > > > with > > > arguments from a noncommutive algebra. Write your own functions and > > > use > > > Format for pretty printing the results. Especially for Power, Exp > > > there > > > are MatrixPower, MatrixExp which have build features you are > > > requiring. > > > > > > regards, Roland > > > > In that case does anyone know how to change the precedence of a > > function > > so it is parenthesied correctly? In other words I want the power > > function to have the same precedence as Power. > > > > Jeff > > -- > > Jeffrey Hersh,PhD > > > > Remove the *NOSPAM* to reply. > > > > <insert amusing quote here> > > > -- Jeffrey Hersh,PhD Remove the *NOSPAM* to reply. <insert amusing quote here>

**References**:**Re: Overriding Power***From:*Jeff Hersh <frumple*NOSPAM*@home.com>