MathGroup Archive 2013

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: Low precision exponentiation

  • To: mathgroup at smc.vnet.net
  • Subject: [mg129849] Re: Low precision exponentiation
  • From: Andrzej Kozlowski <akozlowski at gmail.com>
  • Date: Mon, 18 Feb 2013 06:03:43 -0500 (EST)
  • Delivered-to: l-mathgroup@mail-archive0.wolfram.com
  • Delivered-to: l-mathgroup@wolfram.com
  • Delivered-to: mathgroup-newout@smc.vnet.net
  • Delivered-to: mathgroup-newsend@smc.vnet.net
  • References: <20130217090833.8CF776937@smc.vnet.net>

In Mathematica 2.5 is a machine precision number and applying N to it 
does nothing. You could use SetPrecision but a better way is to use 
exact input:

N[(5/2)^125,30]
5.52714787526044456024726519219*10^49

Andrzej Kozlowski


On 17 Feb 2013, at 10:08, Blaise F Egan <blaise at blaisefegan.me.uk> wrote:

> I am trying to evaluate 2.5^125 to high precision.
>
> R gives 5.527147875260445183346e+49 as the answer but Mathematica with N[2.5^125,30] gives 5.52715*10^49 and says that is to machine precision.
>
> I am inexperienced at Mathematica. Am I doing something silly?
>
> Blaise
>




  • Prev by Date: barchart
  • Next by Date: Re: Low precision exponentiation
  • Previous by thread: Re: Low precision exponentiation
  • Next by thread: Re: Low precision exponentiation