Statalist


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: st: AW: Creating non-overlapping events


From   Kaspar Dardas <kaspar.dardas@googlemail.com>
To   statalist@hsphsun2.harvard.edu
Subject   Re: st: AW: Creating non-overlapping events
Date   Wed, 25 Nov 2009 10:13:35 +0100

Hi guys (Martin & Nick),

thanks to both of you!

I have just run Martin's suggestion and it work fine- it provides
exactly what I need. I looked into -panelthin- and it should give me
the same results. I did not run it though.

Best,

Kaspar



2009/11/25 Nick Cox <n.j.cox@durham.ac.uk>:
> At first sight, it looks as if this is a problem solved by -panelthin- on SSC.
>
> The existence of two dates is not problematic, as they are a fixed time apart.
>
> As I understand it, Kaspar needs to declare his data to be panel data with identifier something like
>
> egen id = group(companyname name)
> tsset id eventdate
>
> and then apply -panelthin-.
>
> Nick
> n.j.cox@durham.ac.uk
>
> Kaspar Dardas
>
> thanks for your promt answer. However, this won't solve my problem.
> Since I  did not describe the problem properly its all on me. Your
> solution is perfect for what I have described.
>
> First, I use the  -by- groups companyname AND name. I need both since
> the same name can appear in a different company,as well. I thought
> that implementing by groups would be easier but with your solution it
> not possible- or, I dont know how to handle it...
>
> Furthermore, a situation might appear where two overlaps exist. (see
> trade 6 and 7). Trade 6 and 7 have to be dropped. However trade 8 is
> fine since it does not interfere with trade 5. I dont think your
> solution will caputre this, or will it?
>
>> 1 "Company A" "Margetts, Rob" 14-Feb-03 06-Mar-03
>> 2 "Company A" "Margetts, Rob" 17-Feb-03 09-Mar-03
>> 3 "Company A" "Margetts, Rob" 14-Nov-03 04-Dec-03
>> 4 "Company A" "Margetts, Rob" 14-May-04 03-Jun-04
>> 5 "Company B" "Michael, Ham" 06-Aug-04 26-Aug-04
>> 6 "Company B" "Michael, Ham" 07-Aug-04 27-Aug-04
>> 7 "Company B" "Michael, Ham" 15-Aug-04 02-Sep-04
>> 8 "Company B" "Michael, Ham" 28-Aug-04 08-Sep-04
>
>
> 2009/11/24 Martin Weiss <martin.weiss1@gmx.de>:
>
>> No sign so far of which -by- groups you want, although I can see that they are relevant here. For the simple example, this is possible code:
>>
>>
>>
>> *************
>> clear*
>>
>> inp byte trade companyname:mylab name:mylab2  /*
>> */  str10(eventdate postdays), auto
>> 1 "Company A" "Margetts, Rob" 14-Feb-03 06-Mar-03
>> 2 "Company A" "Margetts, Rob" 17-Feb-03 09-Mar-03
>> 3 "Company A" "Margetts, Rob" 14-Nov-03 04-Dec-03
>> 4 "Company A" "Margetts, Rob" 14-May-04 03-Jun-04
>> 5 "Company A" "Margetts, Rob" 06-Aug-04 26-Aug-04
>> end
>>
>> compress
>>
>> gen eventdate2=date(eventdate, "DM20Y")
>> format eventdate2 %tdMonth_DD,_CCYY
>> gen postdays2=date(postdays, "DM20Y")
>> format postdays2 %tdMonth_DD,_CCYY
>>
>> drop eventdate postdays
>>
>> gen byte overlap= /*
>> */ eventdate2 < postdays2[_n-1]  /*
>> */ in 2/`=_N'
>>
>> //not just "overlap" as missing in first obs
>> drop if overlap==1
>>
>> list, noobs
>> *************
>
> Kaspar Dardas
>
>> I have the following problem. I need to create a non-overlapping event
>> data set. I have two date variables 1st: "eventdate" which is the
>> start of the event and 2nd: "postdays", which is the end of the event.
>>  The length of the event is exactly 20 days (which is, of course, the
>> difference between "eventdate" and "postdays"). If two events overlap
>> (which happens in trade 1 and 2, in the example below)  I only take
>> the first event and drop the 2nd (trade 2).
>> How can I do this in Stata? I have about 140000 trades, several
>> thousands companies etc....
>>
>> trade         companyname                  name         eventdate
>>  postdays
>> 1               Company A             Margetts, Rob      14-Feb-03
>>  06-Mar-03
>> 2                Company A            Margetts, Rob       17-Feb-03
>>   09-Mar-03
>> 3                Company A            Margetts, Rob      14-Nov-03
>>   04-Dec-03
>> 4                Company A            Margetts, Rob       14-May-04
>>  03-Jun-04
>> 5                 Company A           Margetts, Rob         06-Aug-04
>>   26-Aug-04
>>
>
> *
> *   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/



© Copyright 1996–2014 StataCorp LP   |   Terms of use   |   Privacy   |   Contact us   |   What's new   |   Site index