matlab报错,The integrand function must return an output vector of the same length ...序如下syms f ; la1=1310*10^-9; c=3*10^8; x=0; %光程差 f1=c/la1;df=3.4*10^12; %谱宽la2=1311*10^-9; f2=c/la2;t=sqrt(exp((-(f-f1)*(f-f1)-(f-f2)*(f-f2))/(2*df*