急求解答
 

下面是一个比较简单的lsqcurvefit函数，可是matlab总是报错，请各位高手指点！！！
function f=fun(x,tdata)
f=x(1)/(1+(x(1)/5.70533-1)*exp(-x(2)*(tdata-2001)));


clc,clear;
tdata=[2001,2007,2009];
xdata=[5.70533,23.81030,39.45855];x0=[60,0.2];
x=lsqcurvefit(@fun,x0,tdata,xdata)

错误代码：
??? Error using ==> optim\private\lsqncommon
User supplied function failed with the following error:

Error using ==> mrdivide
Matrix dimensions must agree.