Are you sure?
u New
- (u %. u D.1)
,. (8 + (2 ^ ]) - 2 ^ 2 ^ ])New (^:(<22)) 1
1
3.44167448
3.25190632
3.03819348
2.7974808
2.53114635
2.25407823
2.00897742
1.86069674
1.82070294
1.81842281
1.81841595
1.81841595
1.81841595
1.81841595
1.81841595
1.81841595
1.81841595
1.81841595
1.81841595
1.81841595
1.81841595
(8 + (2 ^ ]) - 2 ^ 2 ^ ]) 1.81841595
_8.21739086e_8
(8 + (2 ^ ]) - 2 ^ 2 ^ ]) 1.75379
1.01615682
PS. Notice that New is a tacit version (not shown) of Louis' VN adverb.
On Sun, Jan 28, 2018 at 5:52 PM, Skip Cave <[email protected]> wrote:
> Raul,
>
> You had it right in the first place.
>
> 0 = 8 + (2^x) - 2^2^x NB. Is correct, and the answer is real
>
> The answer is close to 1.75379
>
> I wanted to know how to construct the Newton Raphson method using the
> iteration verb N described in the link: http://code.jsoftware.
> com/wiki/NYCJUG/2010-11-09
> under "A Sampling of Solvers - Newton's Method"
>
> N=: 1 : '- u % u d. 1'
>
> Skip
>
>
>
>
>
> Skip Cave
> Cave Consulting LLC
>
> On Sun, Jan 28, 2018 at 4:38 PM, Raul Miller <[email protected]>
> wrote:
>
> > Eh... I *think* you meant what would be expressed in J as:
> >
> > 0 = 8 + (2^x) - 2^2^x
> >
> > I'd probably try maybe a few hundred rounds of newton's method first,
> > and see where that leads.
> >
> > But there's an ambiguity where the original expression (depending on
> > the frame of reference of the poster) could have been intended to be:
> >
> > 0 = 8 + (2^x) + _2^2^x
> >
> > [if that is solvable, x might have to be complex]
> >
> > Thanks,
> >
> > --
> > Raul
> >
> > On Sun, Jan 28, 2018 at 5:25 PM, Skip Cave <[email protected]>
> > wrote:
> > > What is the best iterative way to solve this equation:
> > >
> > > (-2^2^x) + (2^x) +8 =0
> > >
> > >
> > > Skip Cave
> > > Cave Consulting LLC
> > > ----------------------------------------------------------------------
> > > For information about J forums see http://www.jsoftware.com/forums.htm
> > ----------------------------------------------------------------------
> > For information about J forums see http://www.jsoftware.com/forums.htm
> ----------------------------------------------------------------------
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>
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