[交流] 【求助】数据拟合

function F=myfun(a,data)
x(1)=data(1,:);
x(2)=data(2,:);
F=a(3)*exp((-a(5))*(x(2)-a(4))/(a(6)+(x(2)-a(4))))/(1+(a(3)*exp((-a(5))*(x(2)-a(4))/(a(6)+(x(2)-a(4))))*x(1)/a(1))^(1-a(2)))
命令窗口程序如下：
>>  x1=[40 60 80 100 150 200 300 400 500 600 800 1000 1200 40 60 80 100 150 200 300 400 500 600 800 1000 1200 40 60 80 100 150 200 300 400 500 600 800 1000 1200 40 60 80 100 150 200 300 400 500 600 800 1000 1200 40 60 80 100 150 200 300 400 500 600 800 1000 1200];
x2=[423.15,423.15,423.15,425.15,425.15,425.15,425.15,425.15,425.15,425.15,425.15,425.15,425.15,431.15,431.15,431.15,431.15,431.15,431.15,431.15,431.15,431.15,431.15,431.15,431.15,431.15,437.15,437.15,437.15,437.15,437.15,437.15,437.15,437.15,437.15,437.15,437.15,437.15,437.15,443.15,443.15,443.15,443.15,443.15,443.15,443.15,443.15,443.15,443.15,443.15,443.15,443.15,449.15,449.15,449.15,449.15,449.15,449.15,449.15,449.15,449.15,449.15,449.15,449.15,449.15];
ydata=[500 367.4 316.4 351 272 249 207 180 128 121 86.2 80.8 69.1 172.9 142.4 122.1 114 95 84 69.2 60 53 48 41.2 36.2 31.6 152.9 122.4 107.1 98 84 71 58.2 51 45.6 41.8 36.4 32.7 30.0 132.5 115.4 101.9 90 76 69 57.1 51 44.9 40.8 35.2 31.0 28.2 112.1 101.9 86.7 82 68 61 50.3 45 41 38 32.6 29 26.2];
data=[x1;x2];
a0=[5000 0.3 3.5*10e13 300 20 1.5];
[a,resnorm]=lsqcurvefit(@myfun,a0,data,ydata)

function F=myfun(a,data)
xx=data(1,:);
xxx=data(2,:);
F=a(3).*exp((-a(5))*(xxx-a(4))./(a(6)+(xxx-a(4))))./(1+(a(3).*exp((-a(5)).*(xxx-a(4))./(a(6)+(xxx-a(4)))).*xx/a(1)).^(1-a(2)))