I see what you mean.
But, as stated, this would bulk up the display unnecessarily.
You could probably add a rule for trimming zero digits, which might
make this palatable, but that would be something different.
--
Raul
On Sat, Mar 10, 2018 at 9:56 AM, 'Bo Jacoby' via Programming
<programm...@jsoftware.com> wrote:
> Yes Raul.
> I do not at all claim that (p5) is better that (p.).
> Perhaps J should always display the same number of decimals for the real part
> and the imaginary part of a complex number, such that the result would read
> _1.00000j0.00000 _1.00000j0.00000
> (%:i.2) is (0 1) , and (%:i.3) is (0 1 1.41421) , but perhaps should be
>
> 0.00000 1.00000 1.41421
> with the same number of decimals in every component of a vector.
>
> See what I mean?
> Thanks.
> Bo.
>
>
>
>
>
>
> Den 15:26 lørdag den 10. marts 2018 skrev Raul Miller
> <rauldmil...@gmail.com>:
>
>
> Looks like you could use another stage to clean up results?
>
> 1 {:: p. 1 2 1
> _1 _1
>
> p5 1 2 1
> _1j1.54593e_9 _1j3.48012e_9
>
> P.S. looking at the source, J is using Laguerre's method (so I'd use
> p.. if I were re-implementing it in J).
>
> Thanks,
>
> --
> Raul
>
>
> On Sat, Mar 10, 2018 at 2:13 AM, 'Bo Jacoby' via Programming
> <programm...@jsoftware.com> wrote:
>> (p.) is OK, but I do not know how it works.
>> Thanks to Raul Miller and to R.E.Boss, my home-cooked equation solver looks
>> like this.
>> p1=.+`*/&}:&|:@(,@,."_ 0) NB. evaluate polynomial x at point y
>> p2=.*/&|:&(+0&=)&(-/~) NB. multiply differences between approximate roots
>> p3=.]-p1%p2@:] NB. iteration step
>> p4=.](p3^:_)0.8j0.6^i.@:<:&$ NB. solve a normalized equation
>> p5=.p4&(%{:)&({.~>:&{:&(-.&(0&=)#i.&#)) NB. normalize and solve
>> NB. This J code can probably be further compacted.
>> NB. test runs:
>> load'plot'
>> pl=:[:'dot;pensize 5'&plot 0j1*] NB. vertical real axis
>> a=. 0 1 2 3 4 5 0 NB. test coefficients
>> pl p5 a NB. show complex roots using (p5)
>> pl >}.p.a NB. show complex roots using (p.)
>> p5 1 NB. show no roots using (p5)
>>
>> p.1 NB. show no roots using (p.)
>> |domain error
>> | p.1
>>
>> Thanks! Bo.
>>
>> Den 20:53 onsdag den 7. marts 2018 skrev R.E. Boss <r.e.b...@outlook.com>:
>>
>>
>> a |:@:(,@,."_ 0) b
>>
>>
>> R.E. Boss
>>
>>
>>> -----Original Message-----
>>> From: Programming <programming-boun...@forums.jsoftware.com> On
>>> Behalf Of 'Bo Jacoby' via Programming
>>> Sent: maandag 5 maart 2018 14:35
>>> To: Programming Forum <programm...@jsoftware.com>
>>> Subject: [Jprogramming] (,a,.2),.,a,.3
>>>
>>> Let (a =. _1 _1 0 0 0 1) and (b =. 2 3).
>>> For my own education I am trying to make a homecooked version of (p.).
>>>
>>> (+`*/}:(,a,.2),.,a,.3) produces the same result as (a p. b) I need a nice
>>> verb (f)
>>> such that (a f b) produces ((,a,.2),.,a,.3) Thanks! Bo.
>>> ----------------------------------------------------------------------
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>>
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