not log2(10) but log(10,2)
{{{
R = RealField(round(log(10,2)*200))
len(str(R(pi)))
///
200
}}}
On 4/17/07, Timothy Clemans <[EMAIL PROTECTED]> wrote:
> I'm confused about what to do.
>
> {{{
> R = RealField(round(log2(10)*200))
> len(str(R(pi)))
> ///
> 42
> }}}
>
> It would be nice if there was a SAGE way to easily get pi to say 200
> binary places or 200 decimal places.
>
> maybe:
> pi.str(2,places=200)
>
> On 4/17/07, William Stein <[EMAIL PROTECTED]> wrote:
> >
> > On 4/17/07, Timothy Clemans <[EMAIL PROTECTED]> wrote:
> > >
> > > http://www.sagemath.org/hg/sage-main?f=258cf90b118f;file=sage/functions/constants.py
> > >
> > > "We can obtain floating point approximations to each of these constants
> > > by coercing into the real field with given precision. For example, to
> > > 200 decimal places we have the following: "
> >
> > That's a mistake in the documentation -- replace "decimal places" by
> > "binary digits". To get n digits you need just over log_2(10) binary
> > digits.
> >
> > >
> > > I have done some tests. R = RealField(200); len(str(R(pi))) "is not
> > > around 200"
> > >
> > >
> > > {{{
> > > R = RealField(100)
> > > print len(str(R(pi)))
> > > print len(str(R(e)))
> > > R = RealField(200)
> > > print len(str(R(pi)))
> > > print len(str(R(e)))
> > > R = RealField(300)
> > > print len(str(R(pi)))
> > > print len(str(R(e)))
> > > R = RealField(400)
> > > print len(str(R(pi)))
> > > print len(str(R(e)))
> > > ///
> > > 30
> > > 30
> > > 60
> > > 60
> > > 91
> > > 91
> > > 121
> > > 121
> > > }}}
> > >
> > > So now how do I get the decimal expansion of say pi to 200 places?\
> >
> > > >
> >
>
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