Create a local system of equations function from a set of anonymous functions

Hello,

I have a set of N anounimous functions which are created using this code

equations = {'@(x1,x2)x1.^2+x2-6','@(x1,x2)-2.5.*x1+x2.^2-2'};%Set your equations 
N = numel(equations);
f = cell(1,N);

for i = 1:N
    f{i} = str2func(equations{i});
end

The thing is, in a later part of the program I would like to use fsolve to solve the system of equation and fsolve requires the a function in this equivalent form:

function F = root2d(x)
F(1) = x(1).^2+x(2)-6;
F(2) = -2.5.*x(1)+x(2).^2-2;
end

where root2d is the function inputted in fsolve. I was wondering if there was a way to create a function in this form from the upper form or a way to use fsolve using the upper form?

Kind regards

Answer 1

[Paul]

One approach:

equations = {'@(x1,x2)x1.^2+x2-6','@(x1,x2)-2.5.*x1+x2.^2-2'};%Set your equations 
N = numel(equations);
f = cell(1,N);
for i = 1:N
    f{i} = str2func(equations{i});
end

F = @(x) cellfun(@(func) func(x(1),x(2)),f)

F = function_handle with value:
    @(x)cellfun(@(func)func(x(1),x(2)),f)

sol1 = fsolve(F,[2 2])

Equation solved.

fsolve completed because the vector of function values is near zero
as measured by the value of the function tolerance, and
the problem appears regular as measured by the gradient.

sol1 = 1×2

1.8509 2.5743

F(sol1)

ans = 1×2

1.0e-13 * -0.0178 0.3109

[f{1}(sol1(1),sol1(2)) , f{2}(sol1(1),sol1(2))]

ans = 1×2

1.0e-13 * -0.0178 0.3109

Answer 2

[Dyuman Joshi]

Another approach (Note - requires Symbolic Toolbox)

equations = {'@(x1,x2) x1.^2+x2-6','@(x1,x2) -2.5.*x1+x2.^2-2'};%Set your equations 

f = str2sym(equations);

z = matlabFunction(f,"File", "root2d", "Vars",{symvar(f)});

out = fsolve(z,[2 2])

Equation solved.

fsolve completed because the vector of function values is near zero
as measured by the value of the function tolerance, and
the problem appears regular as measured by the gradient.

out = 1×2

1.8509 2.5743

z(out)

ans = 1×2

1.0e-13 * -0.0178 0.3109