xtdpdsys DIS SIZE DEMAND LIQ RISK R_A R_H D1 D2, lags(1) maxldep(3) vce(robust)
结果显示 DPD error in calculating columns？？不知问题出在哪


之前没有设置maxldep为3，而是取了默认值，xtdpdsys DIS SIZE DEMAND LIQ RISK R_A R_H D1 D2, lags(1) vce(robust)
结果显示：

                     J():  3900  unable to allocate real <tmp>[8413,29838]
         _xtdpd_dowork():     -  function returned error
                 <istmt>:     -  function returned error

Return code 3900
        out of memory
        Mata is out of memory; the operating system refused to supply
        what Mata requested.  There is no Mata or Stata setting that
        affects this, and so nothing in Mata or Stata to reset in order
        to get more memory.  You must take up the problem with your
        operating system.
这个是因为默认值要取所有可能的被解释变量的滞后项为工具变量，所以导致工具变量太多、内存不足吗？

求大神指点~谢谢