[Date Prev][Date Next][Thread Prev][Thread Next][Date index][Thread index]

From |
"Nick Cox" <[email protected]> |

To |
<[email protected]> |

Subject |
st: RE: Re: Invalid syntax in -xtdes- command |

Date |
Mon, 13 Oct 2003 14:23:32 +0100 |

wastata > > --- In [email protected], "Scott Merryman" <smerryman@k...> > wrote: > > ----- Original Message ----- > > From: "West Addison" <wastata@y...> > > To: <statalist@h...> > > Sent: Friday, October 10, 2003 6:31 PM > > Subject: st: Invalid syntax in -xtdes- command > > > > > > > I have a panel data set and attempted to run the xtdes > > > command on it in Stata version 7 for Windows. The > > > command started to run okay and produced the first few > > > lines of output but then failed with the error message > > > "invalid syntax r(198);". My syntax looks fine as far > > > as I can tell from the manual--I am just typing > > > "xtdes" with no options--by I am new to this command > > > and may be missing something. Is there a bug in > > > xtdes? Here is what my log looks like: > > > > > > . use E:\Projects\HAP\DataSets\analysis.dta > > > > > > . tsset id_number time_from_intake > > > panel variable: id_number, 394 to 1412 > > > time variable: time_from_intake, -24 to 12, > > > but with gaps > > > > > > . xtdes > > > > > > id_number: 394, 399, ..., 1412 > > > n = 288 > > > time_from_intake: -24, -23, ..., 12 > > > T = 37 > > > Delta(time_from_intake) = 1; (12--24)+1 = > > > 37 > > > (id_number*time_from_intake uniquely > > > identifies each observation) > > > > > > Distribution of T_i: min 5% 25% 50% > > > 75% 95% max > > > 1 1 1 3 > > > 5 14 29 > > > invalid syntax > > > r(198); > > > > > > . > > > > The problem is that you have negative time values. If you -set > trace on- and > > then run -xtdes- you will see that it chokes when tries > to create a > new variable > > named _T`time value', but _T-24 is not a valid name. > > > > From the trace: > > > > - gen int _T`i' = 1 if `tvar'==`i' > > = gen int _T-24 = 1 if t==-24 > > invalid syntax > > > > If you create a new time variable, such as > > > > gen time2 = time_ + 24 > > > > xtdes should work fine. > > Thanks, Scott. You seem to a have pinpointed the problem with > xtdes. I would say this is a bug, because the manual, in the entry > for xt, states that negative values of the time variable > are allowed: > "[The time variable] must be a single, numeric variable, although > whether it takes on the values 1, 2, 3 or 1, 7, 9, or even -2, sqrt > (2), pi is irrelevant." > > Thanks again for your help. > > West > > * > * For searches and help try: > * http://www.stata.com/support/faqs/res/findit.html > * http://www.stata.com/support/statalist/faq > * http://www.ats.ucla.edu/stat/stata/ Good point. However, my perspective from a distance is this: 1. I read this as mostly a documentation bug. You can't get far with declaring as a time variable anything with non-integer values. 2. It would seem in addition that there is a specific and implicit assumption in -xtdes- which may well be easily fixable. For example, there is no obvious reason why variables created on the fly should not have names such as _Tm24, etc., for this situation. Nick [email protected] * * For searches and help try: * http://www.stata.com/support/faqs/res/findit.html * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/

**References**:**st: Re: Invalid syntax in -xtdes- command***From:*"wastata" <[email protected]>

- Prev by Date:
**st: RE: bug un makematrix ?** - Next by Date:
**Re: st: RE: bug un makematrix ?** - Previous by thread:
**st: Re: Invalid syntax in -xtdes- command** - Next by thread:
**Re: st: Invalid syntax in -xtdes- command** - Index(es):

© Copyright 1996–2024 StataCorp LLC | Terms of use | Privacy | Contact us | What's new | Site index |