Re: st: date("01jan1960", "DMY") does not seem to work with -if- qualifier of the command -tablist-

[Jeremy Page <miahpage@gmail.com>]

In order to properly close this thread I want to report that this
issue was fixed in the September 1, 2011 update to Stata 11.2.  I
assume that it was fixed in Stata 12 but I do not have access to Stata
12 so I can not test the original code to make sure.  Thank you again
for all the help from Statalist on this topic.

Best,
Jeremy

On Thu, Mar 31, 2011 at 12:25 PM, Nick Cox <n.j.cox@durham.ac.uk> wrote:
>
> Here is another work-around.
>
> gen touse = statadate > date("01Jan1960", "DMY")
> tablist bday name if touse
> groups bday name if touse
>
> That way, the precise -if- condition is evaluated using Stata 10/11 rules.
>
> Nick
> n.j.cox@durham.ac.uk
>
> Jeremy Page
>
> I followed up the Stata technical support and they have indicated that
> this behavior was not intended.  They have forwarded this issue onto
> their development team and they will address it in a future update.  I
> want to thank Michael Mitchell and Nick Cox for their help in tracking
> down the root of the issue.
>
> On Tue, Mar 22, 2011 at 5:05 AM, Nick Cox <njcoxstata@gmail.com> wrote:
>
> > Michael Mitchell's -tablist- is similar in spirit to my -groups-
> > (SSC). (I am not sure that either of us has registered that before
> > now.)
> >
> > FWIW, -groups- behaves similarly on this example:
> >
> > . groups bday name if statadate > date("01Jan1960", "DMY")
> > ---------------------------------------------------------------------
> > begin groups ---
> > - version 8
> > - syntax varlist [if] [in] [fweight aweight/] [, NOObs SUBVARname SUM
> > Compress LABvar(
> >> varname) * FILLin MISSing SHow(str) showhead(str asis) SELect(str) Order(str) FORMat
> >> (str) nby(numlist int >0) ge lt REVerse ]
> > - if "`missing'" == "" marksample touse, strok
> > = if "" == "" marksample touse, strok
> > - else marksample touse, novarlist
> > - qui count if `touse'
> > = qui count if __000001
> > - if r(N) == 0 error 2000
> > no observations
> > -----------------------------------------------------------------------
> > end groups ---
> > r(2000);
> >
> > Under version control the new syntax of -date()- is treated within
> > -marksample- as legal, but it yields missings.
>
> > On Tue, Mar 22, 2011 at 5:40 AM, Kieran McCaul <Kieran.McCaul@uwa.edu.au> wrote:
> >
> >> The old date function syntax used "dmy" not "DMY".
> >> I think you'll find that the following works:
> >>
> >> tablist bday name if statadate > date("01Jan1960", "dmy")
>
> Michael N. Mitchell
>
> >>   This is a most curious issue! Eric provides an excellent solution,
> >> but I was still
> >> flummoxed why the behavior of the -if- condition should be different for
> >> my -tablist-
> >> command as compared to a command like -tabulate-. So, I investigated.
> >>
> >>   The heart of -tablist- is the -contract- command. The -if-
> >> specification is passed from
> >> -tablist- to -contract-, and then within the -contract- command it is
> >> being implemented
> >> via the -marksample- command. So I tested the -marksample- command using
> >> your if condition.
> >>
> >> . clear
> >> . use http://www.stata-press.com/data/r10/datexmpl.dta
> >> . gen statadate = date(bday, "DMY")
> >> . format statadate %td
> >> . local if statadate > date("01Jan1960", "DMY")
> >> . marksample touse, strok novarlist
> >> . list
> >>
> >>      +------------------------------------------------+
> >>      | name          bday    x   statadate   __000004 |
> >>      |------------------------------------------------|
> >>   1. | Bill   21 Jan 1952   22   21jan1952          0 |
> >>   2. |  May   11 Jul 1948   18   11jul1948          0 |
> >>   3. |  Sam   12 Nov 1960   25   12nov1960          1 |
> >>   4. |  Kay    9 Aug 1975   16   09aug1975          1 |
> >>      +------------------------------------------------+
> >>
> >> The temporary variable __000004 properly indicates that Sam and Kay were
> >> born after
> >> 1/1/1960. But, if you look inside the source code of the -contract-
> >> command using
> >> -viewsource contract.ado-, you can see that it is running under version
> >> control, using
> >> -version 6.0-. So, let's try this again, but running the -marksample-
> >> command under
> >> version control.
> >>
> >> . version 6.0, missing : marksample touse, strok novarlist
> >> . list
> >>
> >>      +-----------------------------------------------------------+
> >>      | name          bday    x   statadate   __000004   __000005 |
> >>      |-----------------------------------------------------------|
> >>   1. | Bill   21 Jan 1952   22   21jan1952          0          0 |
> >>   2. |  May   11 Jul 1948   18   11jul1948          0          0 |
> >>   3. |  Sam   12 Nov 1960   25   12nov1960          1          0 |
> >>   4. |  Kay    9 Aug 1975   16   09aug1975          1          0 |
> >>      +-----------------------------------------------------------+
> >>
> >> The new variable created, -__000005-, believes that none of these
> >> children were born after
> >> 1/1/1960.
> >>
> >>   Unfortunately, we cannot trace this any deeper because the
> >> -marksample- command is a
> >> built in command.
> >>
> >>   I think if the -marksample- command (within the -contract- command)
> >> were issued using
> >> version control to bring it to the current version, then I believe that
> >> the behavior of
> >> -contract- with the kind of -if- condition you used would then be
> >> consistent across commands.
>
> On 2011-03-21 5:22 PM, Jeremy Page wrote:
>
> >>> I am a frequent user of the user generated command -tablist- and I
> >>> have run into a behavior that I can not explain.  I am trying to use
> >>> Stata's -date- command with the -if- qualifier to restrict
> >>> observations from displaying in -tablist-.  When I attempt to do this
> >>> there appears to be a problem.  I am able to use the -date- command to
> >>> restrict observations with -tabulate- and I am able to restrict
> >>> observations in -tablist- with a local variable being defined by the
> >>> -date- command but not with -tablist-.  It is my understanding that
> >>> the -if- qualifiers across all programs should act the same.  Am I
> >>> missing something?  I have included an example below using a Stata
> >>> supplied data set.
> >>>
> >>> I am using version 1.2 of -tablist- which can be found at -findit
> >>> tablist- and my version of Stata is 10.1 on a Windows XP machine.
>
> >>> **********begin example***************
> >>> clear
> >>> use http://www.stata-press.com/data/r10/datexmpl.dta
> >>>
> >>>
> >>> gen statadate = date(bday, "DMY")
> >>>
> >>> format statadate %td
> >>>
> >>> list statadate
> >>>
> >>> display date("01Jan1960", "DMY")
> >>>
> >>> ***it works with tabulate
> >>> tab bday name if statadate>  date("01Jan1960", "DMY")
> >>>
> >>>
> >>> ***it works with a local variable
> >>> local dte = date("01Jan1960", "DMY")
> >>> tablist bday name if statadate>  `dte'
> >>>
> >>> ***it does not work with tablist
> >>> tablist bday name if statadate>  date("01Jan1960", "DMY")
> >>>
> >>>
> >>> ************end example***************
>
> *
> *   For searches and help try:
> *   http://www.stata.com/help.cgi?search
> *   http://www.stata.com/support/statalist/faq
> *   http://www.ats.ucla.edu/stat/stata/

*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/