Use of @ in a statement

A couple of years ago, a friend shared an optimization code obtained in this forum. Such code is shown below but i don't know for what I need to use the @ in the following statement: F = @(x) COST(x,tout,Vobs). Can you help me please?

Thanks a lot in advance...

x0 = [0.5 .5 .5];   % Just some Initial Condition
ub = [1 1 1];         % Upper bounds
lb = [0 0 0];         % Lower bounds

F = @(x) COST(x,tout,Vobs);
parameters_calc = fmincon(F,x0,[],[],[],[],lb,ub); %<-- FMINCON is the optimizer
legend({'Experimental Data','Fitted Data'});

% assign the estimated parameters to output variables
alfa_calc=parameters_calc(1);
beta_calc=parameters_calc(2);
lambda_calc=parameters_calc(3);

% Lets calculate the means squared error for future comparisons between
% models
V0=0;
[tout,Vcalc] = ode45(@dVdt,tout,V0,[],alfa_calc,beta_calc,lambda_calc);
MSE=sum((Vcalc-Vobs).^2)./length(Vcalc);

function COST = COST(x,t,Vobs)
A = x(1); %alfa
B = x(2); %beta
L = x(3); %lambda
V0=0;
% Given Vobs (i.e. experimental data), lets find the best parameters for the model:

% The cost function calls the ODE solver.
[tout,Vout] = ode45(@dVdt,t,V0,[],A,B,L);
COST = sum((Vout - Vobs).^2);
h = findobj('tag','solution');
set(h,'ydata',Vout);
title(['alfa = ' num2str(A) '   ' 'beta = ' num2str(B) '    lambda = ' num2str(L)]);
drawnow;

Answer 1

[Alan Weiss]

I am not sure that I understand your question. Perhaps this section of the documentation will enable you to figure it out for yourself.

Alan Weiss

MATLAB mathematical toolbox documentation

[EFREN]

Thanks a lot Alan, that's it.