fsolve for non linear equation

function F=Almalki_HW2_P3(x)

global v V k1 k2 CAin CBin CCin CDin

v=1; V=100; k1=1; k2=1; CAin=1; CBin=2; CCin=0; CDin=0;

F=[v*(CAin-x(1))+V*(-k1*x(1)*x(2));

v*(CBin-x(2))+V*(-k1*x(1)*x(2)-k2*x(1)*x(2));

v*(CCin-x(3))+V*(k1*x(1)*x(2)-k2*x(3)*x(2));

v*(CDin-x(4))+V*(k2*x(3)*x(2))];

x0=[ 0; 0; 0; 0];

options=optimoptions('fsolve','Display','iter');

[x,fval]=fsolve(@Almalki_HW2_P3,x0,options)

end

I typed those code for non linear equations, but when I run the codes, I got this message "Not enough input arguments."

So, do you have any idea

thanks

Answer 1

[Star Strider]

One problem is that you called fsolve inside the function. That is not appropriate. The other is that you use global variables.

Try this instead:

function F=Almalki_HW2_P3(x, v, V, k1, k2, CAin, CBin, CCin, CDin)
v=1; V=100; k1=1; k2=1; CAin=1; CBin=2; CCin=0; CDin=0;
F=[v*(CAin-x(1))+V*(-k1*x(1)*x(2)); 
v*(CBin-x(2))+V*(-k1*x(1)*x(2)-k2*x(1)*x(2));
v*(CCin-x(3))+V*(k1*x(1)*x(2)-k2*x(3)*x(2)); 
v*(CDin-x(4))+V*(k2*x(3)*x(2))];
end

x0=[ 0; 0; 0; 0]+eps;
options=optimoptions('fsolve','Display','iter');
[x,fval]=fsolve(@(x)Almalki_HW2_P3(x, v, V, k1, k2, CAin, CBin, CCin, CDin),x0,options)

I assume here that the other arguments exist in your workspace. I created random scalars for them to test this code. It runs without error.

[Faisal Al-malki]

Thanks for your reply. I copied the same code that you provided me with but unfortunatelly it does not work and shows this message below:

Error: File: Almalki_HW2_P3.m Line: 8 Column: 1

This statement is not inside any function.

(It follows the END that terminates the definition of the function "Almalki_HW2_P3".)

[Star Strider]

The code I posted ran without error, or I would not have posted it.

I have no idea what the problem is, or why it threw the error you posted.

[Faisal Al-malki]

so, any one have any idea how to overcome this issue.

[Faisal Al-malki]

or could you send me the matlab file of this code on my email ([e-mail])

[Star Strider]

Save the function on your MATLAB search path as:

Almalki_HW2_P3.m

Then run the fsolve code.