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Re: A little problem with positive numbers

  • To: mathgroup at smc.vnet.net
  • Subject: [mg18058] Re: [mg18039] A little problem with positive numbers
  • From: "Kevin J. McCann" <kevinmccann at Home.com>
  • Date: Tue, 15 Jun 1999 01:43:20 -0400
  • Delivery-date: Tue Jun 15 08:18:19 1999
  • References: <199906121952.PAA05746@smc.vnet.net.>
  • Sender: owner-wri-mathgroup at wolfram.com

I use the following:

<< Algebra`ReIm`

Then use "Upset" as follows:

Re[x]^=x
Im[x]^=0
Abs[x]^=x

the Upset assignment "^=" essentially tags x or whatever variable you use
with those rules so that when Re, Im, Abs are applied to x, the result is
what you wish.  The Algebra'ReIm' package facilitates some of the related
manipulations.  I have not done this with 4.0 yet, but I have used it
extensively with 3.0.

Kevin

----- Original Message -----
From: attico <nicola at Linuz.sns.it>
To: mathgroup at smc.vnet.net
Subject: [mg18058] [mg18039] A little problem with positive numbers


> How can i say to Mathematica that
> a number im using is a positive one?
> I would like to try with
>
> SetAttributes[x,Positive]
>
> but, with my surprise, ive discovered
> that this attribute is inexistent.
> Someone can help me?
>
> Thanx
>
> Nicola
> nicola at linuz.sns.it
>
>
>


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