使用guass做实证的时候 在下面程序 fxfx12[i,.]=est'; 这句后出现错误 ERROR: no variation in at least one independent variable    D:\gauss9.0\est1.txt(83) : error G0046 : Columns don't match  不能排除  跪求高手解答！

fxfx12=zeros(rows(t1),cols(x));
fxfx12t=zeros(rows(t1),cols(x));
i=1;do until i>rows(t1);
xi=meanc(kk)~t1[i]~meanc(inf);
{Est,errorRE,tRE}=betax(ln(xi),h,y,yibar,x,xibar);
fxfx12[i,.]=est';
fxfx12t[i,.]=tRE';
i=i+1;
endo;