请问各位：
                我用varsoc这个命令时候，为什么有时候有时候不能用？不能用的时候显示下面这个（对于同一组数据同一组变量）：
matsize too small
    You have attempted to create a matrix with too many rows or columns or
    attempted to fit a model with too many variables.  You need to increase
    matsize; it is currently 200.  Use set matsize; see help matsize.

    If you are using factor variables and included an interaction that has
    lots of missing cells, either increase matsize or set emptycells drop to
    reduce the required matrix size; see help set emptycells.

    If you are using factor variables, you might have accidentally treated a
    continuous variable as a categorical, resulting in lots of categories.
    Use the c. operator on such variables.