How to feed additional variables into fsolve function

Hello,

I have a function F = quad(x,REF)

function F = quad(x,REF)
    F(1) = x(3)/((T(1)/x(1))-1) + log(x(2)) - log(dv(1))
    F(2) = x(3)/((T(2)/x(1))-1) + log(x(2)) - log(dv(2))
    F(3) = x(3)/((T(3)/x(1))-1) + log(x(2)) - log(dv(3))
    F(4) = x(3)/((T(4)/x(1))-1) + log(x(2)) - log(dv(4))
    F(5) = x(3)/((T(5)/x(1))-1) + log(x(2)) - log(dv(5))
    F(6) = x(3)/((T(6)/x(1))-1) + log(x(2)) - log(dv(6))
    F(7) = x(3)/((T(7)/x(1))-1) + log(x(2)) - log(dv(7))
    F(8) = x(3)/((T(8)/x(1))-1) + log(x(2)) - log(dv(8))
end

I'd like to feed different dv and T values from the main program and solve. I've tried the below code from another post (modified and played around a bit to no avail). How can I feed dv and T values into the function quad and then use fsolve?

REF = [x,dv,T];
f =@(x) quad(x,REF);

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

% fun(dv,T) = @quad;
x0 = [150,0.045,7.5];
[out,fval] = fsolve(f,x0,options)

This works fine when the T and dv are already in the function quad, but I don't want to manually copy and paste new values of dv and T in.

function F = quad(x)
dv = [3610.30 2040.80 1203.70 483.04 106.03 15.54 3.39 1.97]
T = [-40 -35 -30 -20 0 40 100 135] + 273.15
    F(1) = x(3)/((T(1)/x(1))-1) + log(x(2)) - log(dv(1))
    F(2) = x(3)/((T(2)/x(1))-1) + log(x(2)) - log(dv(2))
    F(3) = x(3)/((T(3)/x(1))-1) + log(x(2)) - log(dv(3))
    F(4) = x(3)/((T(4)/x(1))-1) + log(x(2)) - log(dv(4))
    F(5) = x(3)/((T(5)/x(1))-1) + log(x(2)) - log(dv(5))
    F(6) = x(3)/((T(6)/x(1))-1) + log(x(2)) - log(dv(6))
    F(7) = x(3)/((T(7)/x(1))-1) + log(x(2)) - log(dv(7))
    F(8) = x(3)/((T(8)/x(1))-1) + log(x(2)) - log(dv(8))
end

(CALLED FROM THE MAIN AS:)
fun = @quad;
x0 = [150,0.045,7.5];
[out,fval] = fsolve(fun,x0,options)

Answer 1

[Stephen23]

https://www.mathworks.com/help/optim/ug/passing-extra-parameters.html

dv = [3610.30,2040.80,1203.70,483.04,106.03,15.54,3.39,1.97];
T  = [-40,-35,-30,-20,0,40,100,135] + 273.1;
f  = @(x) myquad(x,dv,T);
x0 = [150,0.045,7.5];
[out,fval] = fsolve(f,x0)

Warning: Trust-region-dogleg algorithm of FSOLVE cannot handle non-square systems; using Levenberg-Marquardt algorithm instead.

No solution found.

fsolve stopped because the last step was ineffective. However, the vector of function
values is not near zero, as measured by the value of the function tolerance. 

out = 1×3

144.8987 0.0415 6.9479

fval = 1×8

0.0407 -0.0012 -0.0232 -0.0576 0.0072 0.0600 0.0089 -0.0349

function F = myquad(x,dv,T)
    F(1) = x(3)/((T(1)/x(1))-1) + log(x(2)) - log(dv(1));
    F(2) = x(3)/((T(2)/x(1))-1) + log(x(2)) - log(dv(2));
    F(3) = x(3)/((T(3)/x(1))-1) + log(x(2)) - log(dv(3));
    F(4) = x(3)/((T(4)/x(1))-1) + log(x(2)) - log(dv(4));
    F(5) = x(3)/((T(5)/x(1))-1) + log(x(2)) - log(dv(5));
    F(6) = x(3)/((T(6)/x(1))-1) + log(x(2)) - log(dv(6));
    F(7) = x(3)/((T(7)/x(1))-1) + log(x(2)) - log(dv(7));
    F(8) = x(3)/((T(8)/x(1))-1) + log(x(2)) - log(dv(8));
end

[Matthew Campbell]

Thanks Stephen. This was exactly what I was looking for. Thanks also for attaching the link - I knew this information would be somewhere, but I wasn't searching for the right terms (such as "extra parameters").

https://www.mathworks.com/help/optim/ug/passing-extra-parameters.html

Answer 2

[Sulaymon Eshkabilov]

Here is a combined and a bit simplified solution:

options = optimoptions('fsolve','Display','iter');
x0 = [150,0.045,7.5];
dv = [3610.30 2040.80 1203.70 483.04 106.03 15.54 3.39 1.97];
T = [-40 -35 -30 -20 0 40 100 135] + 273.15;
[out,fval] = fsolve(@(x)([ x(3)/((T(1)/x(1))-1) + log(x(2)) - log(dv(1));
    x(3)/((T(2)/x(1))-1) + log(x(2)) - log(dv(2));
    x(3)/((T(3)/x(1))-1) + log(x(2)) - log(dv(3));
    x(3)/((T(4)/x(1))-1) + log(x(2)) - log(dv(4));
    x(3)/((T(5)/x(1))-1) + log(x(2)) - log(dv(5));
    x(3)/((T(6)/x(1))-1) + log(x(2)) - log(dv(6));
    x(3)/((T(7)/x(1))-1) + log(x(2)) - log(dv(7));
    x(3)/((T(8)/x(1))-1) + log(x(2)) - log(dv(8));]), x0,options)

[Matthew Campbell]

Hi Sulaymon. Thanks for the reply. This also works when you are not looking to call a separate function.