st: stcox continuous interaction issue stata 10

[Matt Cooper <mattcstats@gmail.com>]

Hi All,

I'm having trouble following this tutorial
http://www.ats.ucla.edu/stat/stata/seminars/stata_survival/default.htm
It is at the line 'stcox age ndrugtx i.treat i.site c.age#c.ndrug,
nohr' that I get stuck.

I'm putting 'xi: ' at the start given I'm using Stata10. It seems to
not like the idea of having the interaction between the two continuous
variables. The interactions with the indicator variables work when I
use '*' instead of '#'. Any feedback appreciated.

. xi: stcox age ndrugtx i.treat i.site c.age#c.ndrug, nohr
i.treat           _Itreat_0-1         (naturally coded; _Itreat_0 omitted)
i.site            _Isite_0-1          (naturally coded; _Isite_0 omitted)
time-series operators not allowed
r(101);

Thanks
Matt

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