ga函数调用

[duanyaodong]

我在求三次B样条曲线外一已知点坐标的点到样条曲线的最短距离时调用了ga函数，程序如下：
i=1;
for m=up_m:1:down_m
k=1;
for d=0:0.01:0.3
j=1;
cun_mindis(i,j)=0;
for n=up_n:1:down_n %在一行上的每一点计算它到B样条曲线的最小值
x=Hx(m,n);
z=Hz(m,n);
[a fval]=ga(@dis,1);
cun_mindis(i,j)=fval;
j=j+1;
end
min_dis(i,k)=min(cun_mindis(i,:));
k=k+1;
end
Rafa(i)=sum(mis_dis(i,:))/(down_n-up_n);%计算此时的粗糙度
i=i+1;
end
function y=dis(x,z,u)
y=((x-0.36109998859720*u^3+3.25*u^2+8.875*u+21.00003998767780)^2+(z-1.71245000056680*u^3-1.4971*u^2-1.361*u+1.89996746693460)^2)^(1/2);
出现以下错误提示：
??? Error using ==> gads\private\makeState
GA cannot continue because user supplied fitness function failed with the following error:
Input argument "u" is undefined.

Error in ==> gads\private\gaunc at 65
state = makeState(GenomeLength,FitnessFcn,options);

Error in ==> ga at 260
[x,fval,exitFlag,output,population,scores] = gaunc(FUN,GenomeLength,options);

Error in ==> draw_simulate at 61
[a fval]=ga(@dis,1);
x和z值不知道能不能读进去，这两个值是已知的，郁闷啊，那位高手指点一二，不胜感激！

[duanyaodong]

其中那个笑脸应该是：

[duanyaodong]

我怎样才能向ga的适应度函数里边传值，[a fval]=ga(@dis,1);
dis函数里边有四个参数，只有一个是变量，其他的三个参数如何送进去？