How i use numerical integration in nonlinear curvefitting ? because integration is not working in nonlinear curve fitting.Is any one give me one example in which numerical integration correctly working with respect to time limits?

x0=[0.5,6,3,5,6,1];
lb=[];
ub=[];
x= lsqcurvefit(@myfun1,x0,xdata,ydata,lb,ub,options)
disp=linspace(xdata(1),xdata(end));
figure(7);plot(xdata,ydata,'ko',disp,myfun1(x,disp),'b-')
axis([-50 50 0 0.015]);
legend('data','fitted exponential')
title('Data and Fitted Curve')

 function F = myfun1(x,xdata)
 T=x(4);    
 F=@(T) x(1).*exp(-((x(2).*xdata-x(3).*T).^2.*xdata + x(5).^2.*xdata)/2.*x(6).*xdata);
 F=integral(F,-T,T,'ArrayValued',true);
 F=double(F);

[Torsten]

You mean

function F = myfun1(x,xdata)
 T1=x(4);    
 F=@(T) x(1).*exp(-((x(2).*xdata-x(3).*T).^2.*xdata + x(5).^2.*xdata)/2.*x(6).*xdata);
 F=integral(F,-T1,T1,'ArrayValued',true);

?