求救,各位大侠！
小弟编了一个程序，不过运行不出来，大家帮我看看是哪里出错了啊？function yy=modelA(beta0,X)
a=beta0(1);
b=beta0(2);
c=beta0(3);
d=beta0(4);
x1=X(:,1);
x2=X(:,2);
x3=X(:,3);
x4=X(:,4);
X=[1 11345 8.5491e+006 2.9039e+006
1 13211 1.1048e+006 1.086e+006
1 5405 1.8022e+005 1.7436e+005
1 2321.7 13395 13395
1 7065.4 1.0538e+006 1.0164e+006
1 8119.5 1.1806e+006 1.1057e+006
1 9978.1 9.637e+005 9.1287e+005
1 9163.2 3.474e+006 3.1845e+006
1 11471 2.7904e+006 2.6752e+006
1 19719 1.1219e+006 1.0796e+006
1 23636 1.0319e+006 9.9259e+005
1 9703.8 6.2497e+005 5.3039e+005
1 8303.7 1.2294e+006 1.1015e+006
1 7617.1 2.9071e+006 2.8275e+006
1 6204 8.9299e+005 8.7078e+005
1 13361 1.634e+006 1.5823e+006
1 6071.3 6.8781e+005 6.2794e+005
1 6875.9 1.6384e+006 1.5595e+006
1 9170.1 2.1791e+006 2.0892e+006
1 7781.2 3.9413e+005 3.748e+005
1 11374 84795 84795];
Y=[6620.6
2152.3
4743
4021.3
4346
3589.2
2889
4862.7
4119.9
1906.2
3837.1
2608
3020.5
35026
3915.8
7296
5779.9
4488.7
4367.3
4855.1
3454.2];
yy=a*x1+b*x2+c*x3+d*x4;
beta0=[8138.5 0.12 -0.012 -0.06];
betafit=nlinfit(X,Y,'model',beta0)
