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Re: Descending order

  • To: mathgroup at smc.vnet.net
  • Subject: [mg71772] Re: Descending order
  • From: "dimitris" <dimmechan at yahoo.com>
  • Date: Tue, 28 Nov 2006 06:04:27 -0500 (EST)
  • References: <ekecm8$p4$1@smc.vnet.net>

The trivial answer is: Use TraditionalForm

FrontEndExecute[{HelpBrowserLookup["MainBook", "1.10.9"]}]

defpol=x^4+x^3+x^2+x

\!\(x + x\^2 + x\^3 + x\^4\)

TraditionalForm[defpol]

\!\(TraditionalForm\`x\^4 + x\^3 + x\^2 + x\)

The clever answer is to use the following lines below which ensure a
polynomial is written in the opposite order from the usual Format.

These lines have taken from the following link
http://www.verbeia.com/mathematica/tips/HTMLLinks/Tricks_A-K_32.html

Unprotect[Plus];
HoldPattern[Plus[p__]] := Module[{s1, s2}, s1 = Hold[p]; s2 =
Reverse[s1];
ReplacePart[HoldForm[Evaluate[s2]], Plus, {1, 0}] /;
      OrderedQ[s1] && s1 =!= s2];


Expand[defpol]
\!\(\*
  TagBox[\(x\^4 + x\^3 + x\^2 + x\),
    HoldForm]\)

Note however that

FullForm[%]
HoldForm[Plus[Power[1,4],Power[1,3],Power[1,2],1]]

The normal convention is restored by

HoldPattern[Plus[p__]] =. ;
Protect[Plus];

I higly suggest you to download the Supplementary Help Browser of Ted
Ersek
(which above code belong to) from the following link

http://library.wolfram.com/infocenter/MathSource/4557/

If you want you can make this to be part of your help browser.

Contact me for more details.

Regards
Dimitris



Bruno Campanini wrote:
> After Evaluation, is it possible to have Mathematica 5.2
> ordering descending instead of ascending?
>
> I.e.
>             x^4 + x^3 + x^2 + x
> instead of
>             x + x^2 + x^3 + x^4
> 
> Bruno


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