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Topic: Low precision exponentiation
Replies: 5   Last Post: Feb 19, 2013 6:51 PM

 Messages: [ Previous | Next ]
 Andrzej Kozlowski Posts: 226 Registered: 1/29/05
Re: Low precision exponentiation
Posted: Feb 18, 2013 6:00 AM

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@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
>

Date Subject Author
2/18/13 Sseziwa Mukasa
2/18/13 Andrzej Kozlowski
2/18/13 Bob Hanlon
2/18/13 Murray Eisenberg
2/19/13 Dana DeLouis