matlab做非线性规划，可不可以用二维变量

x1 x2 x3 这样肯定是可以的
下面给你一个例子吧

function [c,ceq]=xiandaicon(x) %构造约束函数
%改进后的关联函数如下
y=[-1.5+0.071346*x(1)+0.19437*x(2)+0.15195*x(3)+0.12264*x(4)+0.086001*x(5)+0.10297*x(6)+0.16082*x(7)+0.10991*x(8);
-1.2+0.070138*x(1)+0.19148*x(2)+0.15361*x(3)+0.12435*x(4)+0.086489*x(5)+0.10241*x(6)+0.16179*x(7)+0.10972*x(8);
-1.3+0.066166*x(1)+ 0.18793*x(2)+0.14325*x(3)+0.12858*x(4)+0.095498*x(5)+0.09618*x(6)+0.16678*x(7)+0.11562*x(8);
-1+0.060249*x(1)+0.18533*x(2)+0.11722*x(3)+0.14637*x(4)+0.084807*x(5)+0.13065*x(6)+0.14866*x(7)+0.12672*x(8);
-1.2+0.039522*x(1)+0.20281*x(2)+0.11388*x(3)+0.12272*x(4)+0.092564*x(5)+0.14821*x(6)+0.14613*x(7)+0.13417*x(8);
-1.2+0.038152*x(1)+0.22594*x(2)+0.11997*x(3)+0.11022*x(4)+0.094532*x(5)+0.13565*x(6)+0.14413*x(7)+0.13141*x(8);
-1.4+0.058904*x(1)+0.19488*x(2)+0.12552*x(3)+0.14836*x(4)+0.072667*x(5)+0.11203*x(6)+0.14754*x(7)+0.1401*x(8);
-1.3+0.059956*x(1)+0.22384*x(2)+0.13336*x(3)+0.13626*x(4)+0.083576*x(5)+