Re: Re: Overriding Power

*To*: mathgroup at smc.vnet.net*Subject*: [mg26926] Re: [mg26868] Re: Overriding Power*From*: Carl Woll <carlw at u.washington.edu>*Date*: Fri, 26 Jan 2001 23:30:03 -0500 (EST)*References*: <94m9e5$3nu@smc.vnet.net> <94oh4k$ee1@smc.vnet.net> <200101260627.BAA18659@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

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>

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