请问这是garch-bekk 的正确算法吗， book2为原始数据，
proc import out =book2
datafile='D:\2013the\book2.xlsx'
dbms=excel2000 replace;
run;
proc varmax data=book2;
model y1 y2;   
garch q=1 p= 1 form=bekk;
run;