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Re: Approximate Zero Times A Symbol

• To: mathgroup at smc.vnet.net
• Subject: [mg127073] Re: Approximate Zero Times A Symbol
• From: Bob Hanlon <hanlonr357 at gmail.com>
• Date: Thu, 28 Jun 2012 04:03:03 -0400 (EDT)
• Delivered-to: l-mathgroup@mail-archive0.wolfram.com
• References: <201206270811.EAA18698@smc.vnet.net>

Use Rationalize

expr = 0. x + 1. y;

expr // Rationalize

y

expr // Rationalize[#, 0] &

y

If there are any rational factors remaining you can use N with any
desired precision to return to reals.


Bob Hanlon


On Wed, Jun 27, 2012 at 4:11 AM, djmpark <djmpark at comcast.net> wrote:
>
> What is the justification for the following?
>
>
>
> 0. x + 1. y
>
>
>
> 0. + 1. y
>
>
>
> I want to display a dynamic weighted sum of x and y and sometimes one of the
> coefficients becomes zero. I would like to keep both terms (for a steady
> display) and format with NumberForm.  If Mathematica is going to drop the x,
> why doesn't it at least also drop the approximate zero?
>
>
>
> If I use SetPrecision we obtain:
>
>
>
> SetPrecision[0. x + 1. y, 10]
>
>
>
> 1.000000000 y
>
>
>
> which is at least more consistent, but not what I want either.
>
>
>
> David Park
>
> djmpark at comcast.net
>
> http://home.comcast.net/~djmpark/index.html

• References:
  • Approximate Zero Times A Symbol
    • From: "djmpark" <djmpark@comcast.net>