How to put fsolve in a loop, using 2 unknowns?

Hi,

I want to write a code that asks fsolve to go through some combinations of guesses and then find all the roots (xdot, ydot) to the equation, but I'm having some trouble debugging the code. I defined the function locally, without saving it in a separate file.

Thanks in advance,

H = @(xdot, ydot) fsolve_root_finding(xdot, ydot);
for xdot = linspace(1,5,5)
  for ydot = linspace(-5,-1,5)
    [ my_root, fval, exit_flag ] = fsolve( H, [ xdot, ydot ] )
    plot( my_root, 'bx','MarkerSize',10 ); 
  end
  hold on
end
   
function G = fsolve_root_finding(xdot, ydot)
  G(1) = xdot + ydot;
end

Here's the current error message:

Not enough input arguments.

Error in fsolve_practice>@(xdot,ydot)fsolve_root_finding(xdot,ydot)

Error in fsolve (line 242)
            fuser = feval(funfcn{3},x,varargin{:});

Error in fsolve_practice (line 9)
[ my_root, fval, exit_flag ] = fsolve( H, [ xdot, ydot ] )

Caused by:
    Failure in initial objective function evaluation. FSOLVE cannot continue.

Answer 1

[Sargondjani]

Replace the first line with:

H = @(X)fsolve_root_finding(X(1),X(2));