Re: how to work with arbitrary precision and accuracy?

[Arnau Mir Torres]

Paul Kienzle wrote:

> You could try the symbolic extensions in octave-forge (http://octave.sf.net).
> See main/symbolic/doc/symbolic.html, wherein it says:
>
>   In  order to do exact arithmetic you need to deal with strings and the vpa
>   command.   For  example:   vpa("1")/vpa("7")  is represented internally as
>   exactly  1/7.   However,  vpa("1")/7 or 1/vpa("7")  is an approximation to
>   1/7  that  is  accurate  to  roughly  the accuracy of the current value of
>   digits.
>
>   Pi is the symbolic value of pi.
>
> Paul Kienzle
> address@hidden
>
> On Sun, May 12, 2002 at 06:36:16PM +0200, address@hidden wrote:
>  
>
> > Hello.
> > I don't know if octave can do this. My question is about to work with an 
> > arbitrary precission and accuracy with octave.
> > For example, if I do:
> > output_precision = 32
> > and next I do
> > pi
> > octave responses:
> > 3.1415926535897931159979634685442e+00
> > but this number only has 16 numbers correctly.
> > What have to do if I work with 32 numbers?
> >
> > Thanks in advance,
> >
> > Arnau.
> >
> >
> >
> >
> > -------------------------------------------------------------
> > Octave is freely available under the terms of the GNU GPL.
> >
> > Octave's home on the web:  http://www.octave.org
> > How to fund new projects:  http://www.octave.org/funding.html
> > Subscription information:  http://www.octave.org/archive.html
> > -------------------------------------------------------------
> >
> >    
Thank you for your response.
I don't want to make symbolic calculations. I want to do numerical 
calculations using 32 numbers of precission, for example.
So, If I do

output_precision = 32

and netx, I do
sqrt(2)*2,
octave only shows 16 numbers correcty, not 32.

Thanks in advance,

Arnau.

--
Arnau Mir Torres
Departament de Matem?tiques i Inform?tica
Universitat de les Illes Balears
Edifici A. Turmeda
Ctra. de Valldemossa, km. 7,5
E-07071 Palma de Mallorca
Spain
Phone: 00 34 971 172561
Fax: 00 34 971 173003
e-mail: address@hidden
http://dmi.uib.es/people/dmiamt0





-------------------------------------------------------------
Octave is freely available under the terms of the GNU GPL.

Octave's home on the web:  http://www.octave.org
How to fund new projects:  http://www.octave.org/funding.html
Subscription information:  http://www.octave.org/archive.html
-------------------------------------------------------------