tsfill只是生成缺失值，并不生成0.
tsfill is used to fill in gaps in time-series data and gaps in panel data with new observations, which contain
    missing values.

如果你要把缺失的部分变成0还是需要我上面提供的那个命令。

楼主，我也是这种情况，缺失一年数据，请问最后怎么补呢？

    Setup
        . webuse ipolxmpl2, clear

    Show years for which the circulation data are missing
        . tabulate circ year if circ == ., missing

    Create icirc containing a linear interpolation of circ on year for missing values of circ and perform this
    calculation separately for each magazine
        . by magazine: ipolate circ year, gen(icirc)
用插值法填补

亲，我也是刚接触，啥子都不懂哈，我想问一下tsfill是根据什么原理生成的缺失值呢