Attempted to access y(3); index out of bounds because numel(y)=2.

[cnhacker]

我在程序调试中遇到了一下问题，请大家多多帮忙。 先 thanks！

??? Attempted to access y(3); index out of bounds because numel(y)=2.

Error in ==> li9_5_4 at 14
dy(3)=(-i*w-eta*J*(1+2*n))*y(3)+eta*J*(1+2*n)*y(4)-2*delta*epsilon/(delta^2+epsilon^2)*J*(n*y(1)-(1+n)*y(2));