[scilab-Users] Re: Re: Can u help to write the code scilab to solve the transcendantal equation by Newton Raphson?

[Michaël Baudin]

Oups, did not see the message by Stéphane Mottelet...

Regards,

Michaël

Le 14/01/2011 15:51, Michaël Baudin a écrit :
> Hi,
>
> That is true. But why not using the fsolve function ?
>
> After all, the whole purpose of Scilab is to save time by providing 
> these "basic" algorithms, isn'it ?
>
> Best regards,
>
> Michaël Baudin
>
> Le 14/01/2011 08:48, JOSE KANTOLE a écrit :
>> Thank you for your feedback!
>>
>> On 1/13/11, Wojciech Artichowicz<w_artichowicz at o2.pl>  wrote:
>>> Hello there,
>>>
>>>
>>>
>>> Here You have a quite general Newton-Raphson function.
>>>
>>> Just fill function F(x) and use the code below. :]
>>>
>>> good luck and best regards.
>>>
>>>
>>>
>>> function y=F(x)
>>>
>>>    y=your formula;
>>>
>>> endfunction
>>>
>>>
>>>
>>> function x1=NewtonRaphson(f,x0,Epsf,Epsx,h)
>>>
>>>    x1=x0;
>>>
>>>    if h==[] then, h=1e-10; end; //step for numerical derivative 
>>> computation
>>>
>>>    while abs(f(x1))>Epsf | abs(x1-x0)>Epsx do //checking the 
>>> condition to
>>> finish iterations
>>>
>>>      x0=x1;
>>>
>>>      df=(f(x0+h)-f(x0-h))/(2.0*h); //numerical derivative (central 
>>> scheme)
>>>
>>>      x1=x0-f(x0)/df;
>>>
>>>    end
>>>
>>> endfunction
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>> x0 = starting value,
>>>
>>> Epsf=0.0000000001;
>>>
>>> Epsx=0.00000001;
>>>
>>> h=0.0000000001;
>>>
>>> solution=NewtonRaphson(F,x0,Epsf,Epsx,h);
>>>
>>>
>
>


-- 
Michaël Baudin
Ingénieur de développement
michael.baudin at scilab.org
-------------------------
Consortium Scilab - Digiteo
Domaine de Voluceau - Rocquencourt
B.P. 105 - 78153 Le Chesnay Cedex
Tel. : 01 39 63 56 87 - Fax : 01 39 63 55 94