Notice: On April 23, 2014, Statalist moved from an email list to a forum, based at statalist.org.
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: st: Mark observation if date variable is between some range
From
Sergiy Radyakin <[email protected]>
To
"[email protected]" <[email protected]>
Subject
Re: st: Mark observation if date variable is between some range
Date
Tue, 13 Aug 2013 18:30:29 -0400
Nick, the question is how to create a pool of candidates (date) for
the condition you posted. Suppose the end of the period is 100 years
from begin. That makes it close to a hundred candidates to probe.
Fortunately in this case we know that any period longer than a year
would contain any given day for certain, so we don't need to probe
anything when endorig-begorig>=366.
The interesting case is to find the candidates within the remaining
situations. I see two candidates, 30jun in the year of begorig and
30jun in the year of endorig.
My solution is here:
do http://radyakin.org/statalist/2013081301/dateinrange2.do
Roberto should be careful that although this solution seems to work
fine for June 30, it would NOT work for February 29, for apparent
reasons.
This is also an example of the nested cond() for the discussion
started last week
http://www.stata.com/statalist/archive/2013-08/msg00351.html
Best, Sergiy Radyakin
On Tue, Aug 13, 2013 at 5:39 PM, Nick Cox <[email protected]> wrote:
> Think of your birthday. Does it define a single date? No, it defines a
> set of dates.
>
> Either way, Stata doesn't regard a day-month as a date, but that need
> not stand in your way. Your condition is just something like
>
> ... if month(date) == 12 & day(date) == 25
>
> and you can add extra condition(s) in terms of -year(date)- if you wish.
> Nick
> [email protected]
>
>
> On 13 August 2013 22:33, Roberto Ferrer <[email protected]> wrote:
>> Nick and Sergiy,
>>
>> Thank you for your replies.
>>
>> Indeed, a typo in my first post.
>>
>> Is there a way in which I can specify the probe as only day-month (no
>> year)? In case of an episode that spans two+ years, one appearance
>> would be enough to set the mark.
>>
>> Could one strategy be create a series of probes for each observation
>> (based on the number of years spanning the episode) and to test them?
>> In a loop maybe.
>>
>> A similar problem I think arises with -tin()- and -twithin()-. Is it
>> not possible to represent day-month as a date in Stata? I haven't been
>> able to find an example.
>>
>>
>>
>>
>>
>> On Tue, Aug 13, 2013 at 9:29 PM, Sergiy Radyakin <[email protected]> wrote:
>>> Roberto, if your variable is numeric variable formatted as date, you
>>> should not be seeing "31feb1999" as you show in the output. February
>>> 31 is an impossible date in any year.
>>>
>>> Given that that is just a typo, all you need is
>>> inrange(candidate,beg,end). Most of the following program generates
>>> the data (that you already have) before applying inrange().
>>>
>>> do http://radyakin.org/statalist/2013081301/dateinrange.do
>>>
>>> +----------------------------------------+
>>> | begorig endorig probe marker |
>>> |----------------------------------------|
>>> 1. | 01jan1998 31dec1998 14067 1 |
>>> 2. | 01oct1998 05jul1999 14246 1 |
>>> 3. | 01jan1999 21feb1999 15041 0 |
>>> +----------------------------------------+
>>>
>>> The variable probe may of course vary by observation, or may be a constant:
>>> generate sprobe="30jun1999"
>>> (instead of the second input statement).
>>>
>>> Best, Sergiy
>>>
>>>
>>>
>>>
>>> On Tue, Aug 13, 2013 at 4:00 PM, Nick Cox <[email protected]> wrote:
>>>> See -help tin()- and -help twithin()-
>>>> Nick
>>>> [email protected]
>>>>
>>>>
>>>> On 13 August 2013 20:54, Roberto Ferrer <[email protected]> wrote:
>>>>> I have date variables (type: numeric daily date (int)) that define
>>>>> the beginning and end of an episode for any observation:
>>>>>
>>>>> begorig endorig
>>>>> 01jan1998 31dec1998
>>>>> 01oct1998 05jul1999
>>>>> 01jan1999 31feb1999
>>>>>
>>>>> I'd like to mark the observation (with some dummy variable) if say,
>>>>> the day 30jun is between -begorig- and -endorig-. Note that the years
>>>>> in any episode are not necessarily the same.
>>>>>
>>>>> Below is something I wrote which does not work. I think I found the
>>>>> mistake but have not yet corrected it. Before doing that, can someone
>>>>> suggest an alternative way?
>>>>>
>>>>> local d 30
>>>>> local m 6
>>>>>
>>>>> gen dummy = 0
>>>>>
>>>>> /*
>>>>> If -begorig- and -endorig- have different years the possibilities are:
>>>>> ------------------------
>>>>> -begorig- and -endorig-
>>>>> ------------------------
>>>>> 1. before and anything --> MARK
>>>>> 2. after and after --> MARK
>>>>> 3. after and before --> do nothing
>>>>> */
>>>>> replace dummy = 1 if ///
>>>>> year(begorig) < year(endorig) & ///
>>>>> day(begorig) <= `d' & month(begorig) <= `m' ///
>>>>> | ///
>>>>> year(begorig) < year(endorig) & ///
>>>>> day(begorig) >= `d' & month(begorig) >= `m' & ///
>>>>> day(endorig) >= `d' & month(endorig) >= `m'
>>>>>
>>>>> /*
>>>>> If -begorig- and -endorig- have the same year the possibilities are:
>>>>> -----------------------
>>>>> -begorig- and -endorig-
>>>>> -----------------------
>>>>> 1. before and before --> do nothing
>>>>> 2. before and after --> MARK
>>>>> 3. after and after --> do nothing
>>>>> 4. after and before --> not possible
>>>>> */
>>>>> replace dummy = 1 if year(begorig) == year(endorig) & ///
>>>>> day(begorig) <= `d' & month(begorig) <= `m' & ///
>>>>> day(endorig) >= `d' & month(endorig) >= `m'
>>>>>
>>>>>
>>>>> Thank you.
>>>>> *
>>>>> * For searches and help try:
>>>>> * http://www.stata.com/help.cgi?search
>>>>> * http://www.stata.com/support/faqs/resources/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/faqs/resources/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/faqs/resources/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/faqs/resources/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/faqs/resources/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/faqs/resources/statalist-faq/
* http://www.ats.ucla.edu/stat/stata/