Re: [Jprogramming] Derivatives

[Lippu Esa]

Hello Brian and others,

After finding the first root x1 you can deflate the original equation by 
dividing it by (x-x1) .

Esa

load'math/calculus'
   Newton =: adverb : ']-u%(u deriv_jcalculus_ 1)'(^:_)("0)
   (+:-^~) Newton 0.5
0.346323
   ((+:-^~)%-&0.346323) Newton 1
2

-----Original Message-----
From: Programming <programming-boun...@forums.jsoftware.com> On Behalf Of Brian 
Schott
Sent: Thursday, February 6, 2020 5:37 PM
To: Programming forum <programm...@jsoftware.com>
Subject: Re: [Jprogramming] Derivatives

Henry et al,

I have 2 questions.

How would the second root at 2 be found with Skip's problem?
Why do I get the following error?

server:~ brian$ /Users/brian/j901/bin/jconsole ; exit;
   JVERSION
Engine: j901/j64avx/darwin
Release-c: commercial/2020-01-11T12:22:31
Library: 9.01.20
Platform: Darwin 64
Installer: J901 install
InstallPath: /users/brian/j901
Contact: 
https://eur01.safelinks.protection.outlook.com/?url=www.jsoftware.com&amp;data=01%7C01%7C%7Ca4360fdf06d04315f06408d7ab1a67e8%7C5090e269dbea4e98a9aa3e70be5890f7%7C0&amp;sdata=UlpDiyWQjhs45mLWkN5AB2cjm%2BhJ%2F3fMK1%2FO3%2B4526U%3D&amp;reserved=0
   load'math/calculus'
   Newton =: adverb : ']-u%(u deriv_jcalculus_ 1)'(^:_)("0)
   (^~ - +:) Newton 0.5
|domain error: deriv_jcalculus_
|       13!:8(3)

Thanks,

On Wed, Feb 5, 2020 at 7:34 AM Henry Rich <henryhr...@gmail.com> wrote:

> I misread your function.
>
>     (^~ - +:) Newton 1.1
> 0.346323j1.2326e_32
>     (^~ - +:) Newton 0.5
> 0.346323
>
> Still need those guardrails!
>
> Henry Rich
>
> --
(B=)
----------------------------------------------------------------------
For information about J forums see 
https://eur01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.jsoftware.com%2Fforums.htm&amp;data=01%7C01%7C%7Ca4360fdf06d04315f06408d7ab1a67e8%7C5090e269dbea4e98a9aa3e70be5890f7%7C0&amp;sdata=r6Q3MQSoFbscOBuJ8f6BocRAZliLs0muaXtijb0vFZ8%3D&amp;reserved=0

Tämän viestin sisältö liitteineen on luottamuksellinen ja tarkoitettu vain sen 
vastaanottajalle. Jos et ole viestin tarkoitettu vastaanottaja, pyydämme sinua 
poistamaan viestin liitteineen ja sen jälkeen ilmoittamaan asiasta välittömästi 
viestin lähettäjälle. Viestin sisällön paljastaminen, kopioiminen tai muu 
käyttö on kielletty.

The contents of this message and any attachments are confidential and meant 
solely for the intended recipient. If you are not the intended recipient, we 
kindly ask that you delete the message and its attachments, and immediately 
notify the sender of the email. Disclosing, copying or using the contents of 
the message is strictly prohibited.
----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm