[Scilab-users] Having a Problem with fsolve

[rsherry8]

Thank you for your response. I am trying to  solve the following system 
of equations:
     x^2 + y^2 = 0
     x^4 + y^4 - 10 = 0

I defined the following function in SciLab:
         function y=f3(x,y)
             y = [x^2+y^2,x^4+y^4-10]
         endfunction

That appeared to work. I found that f3(1,1) is:    2.  -8.
So I then ran the following:
     fsolve([0,0], f3 )
and I got:
     fsolve: exception caught in 'fct' subroutine.
     at line     2 of function f3
     in builtin                fsolve

     Undefined variable: y

I then defined the function fct as follows:
     function y=fct(x,y)
         y = [2*x+2*y, 4*x^3+4*y^3]
     endfunction

I then ran the command:
     fsolve([0,0], f3, fct )
and that produced the following message:
     fsolve: exception caught in 'jac' subroutine.
     at line     2 of function f3
     in builtin                fsolve

     Undefined variable: y

Any additional comments?
Thanks,
Bob

On 10/15/2018 8:14 PM, Samuel Gougeon wrote:
> Le 16/10/2018 à 02:00, rsherry8 a écrit :
>> You Wrote:
>>
>>     If it is provided, g2() must be the jacobian of g1(): it must 
>> compute and evaluate the partial derivatives of g1(), with respect to 
>> x and to y.
>>     That's definitely not the case with your g2(). It should rather 
>> return something like [2*x 2*y].
>>
>> I do not understand this because I am trying to solve a system of 
>> equations and g2 represents the second equation. I suspect I am 
>> missing something.
>>
>> I do not know French.
>
> You may mimic the given example #3. You do not need to speak french to 
> try and test the given code, understand, and imitate it for your own 
> case.
>
> BR
>
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