lsqcurvefit error Too many input arguments.

I'm trying to use lsqcurvefit to find the best parameters b and k that minimize the error between the experimental and numerical solution, when I run this function I get the error.

Error using ex1>@(bk)T0/J2-(bk(1)/J2).*y(:,4)-((bk(2)/J2).*(y(:,2)-y(:,1))). Too many input arguments.

How can I get lsqcurvefit to run with my fun?

T = load('samples.txt');
xdata = T(:,1);
y2data = T(:,3);
 findbk = @(t,y,b,k) [y(3);y(4);k/J1 * y(2) - k/J1 * y(1);T0/J2 - b*y(4)/J2 - (k/J2)*(y(2)-y(1))]; %ode i need to integrate
  [t,y] = ode45(@(t,y) findbk(t,y,1,2),[0:0.01:10],[0,0,0,0]); % integrate ode y (1 and 2 are guesses of b and k)
   
  fun = @(bk) T0/J2 - (bk(1)/J2).*y(:,4) - ((bk(2)/J2).*(y(:,2)-y(:,1))); %define function with b and k uknown
    X = lsqcurvefit(fun,[0,0],xdata,y2data);

[Star Strider]

I demonstrated how to do this correctly in Loop over ode45 to find minimum of a parameter and even gave a complete code example, with adaptations for the posted differential equation system.

.

[Clara Casado-Coterillo]

I do not understand the relation of the answer with the question.

I have the same problem with lsqcurvefit.

if I define the local function first

as local_fun = @(x,xdata)fun(x0,xdata,parm1,param2,parm3,ymaxVector);

and then introduce this into

[x,resn,error,jacobian]=lsqcurvefit(local_fun,x0,xdata,ydata,[],[],options)

it returns x = x0 (previously optimized using PSO or given as data);

if I introduce directly the function :

[x,resn,error,jacobian]=lsqcurvefit(@fun,x0,xdata,ydata,[],[],options,parm1,param2,parm3,ymaxVector);

it returns:

FUN must have two input arguments.

if I introduce the function in lsqcurvefit as:

[x,resn,error,jacobian]=lsqcurvefit(@(x,xdata)fun(x,xdata,ydata,parm1,param2,parm3,ymaxVector),x0,xdata,ydata,[],[],options)

it returns:

Too many input arguments.

i do not know what to try next.

[Walter Roberson]

local_fun = @(x,xdata)fun(x0,xdata,parm1,param2,parm3,ymaxVector);

6 parameters passed. Third parameter is parm1

[x,resn,error,jacobian]=lsqcurvefit(@(x,xdata)fun(x,xdata,ydata,parm1,param2,parm3,ymaxVector),x0,xdata,ydata,[],[],options)

7 parameters passed. Third parameter is ydata, and parm1 is the 4th parameter.