no room to add more variables
    An attempt was made to add a variable that would have resulted in more than
    5000 or 4999 variables (Stata reserves one variable for its own use).  You
    have the following alternatives:
     1.  Drop some variables; see help drop.
     2.  If you are using Stata/SE, increase maxvar; see help maxvar.
遇到以上情况了，用set matsize 800 结果还是这样。
怎么办啊？求助各位大侠！
谢谢啦