[R] New var

peter dalgaard
2017-06-03T08:01:32Z

As Bert says/implies, "some assembly is required".

as.Date() is your friend and you can basically just subtract those to get
differences.  Also, it seems to me that you are really trying to convert
differences to a factor, and then represent the factor using particular dummy
variables for successive differences, for use in a linear model of sorts. A
combination of cut() and a contrast matrix (see contrasts<-) might be a
better structured approach.

-pd

> On 3 Jun 2017, at 07:13 , Bert Gunter <bgunter.4567 at gmail.com>
wrote:
>
> Ii is difficult to provide useful help, because you have failed to
> read and follow the posting guide. In particular:
>
> 1. Plain text, not HTML.
> 2. Use dput() or provide code to create your example. Text printouts
> such as that which you gave require some work to wrangle into into an
> example that we can test.
>
> Specifically:
>
> 3. Have you gone through any R tutorials?-- it sure doesn't look like
> it. We do expect some effort to learn R before posting.
>
> 4. What is the format of your date columns? character, factors,
> POSIX,...? See ?date-time for details. Note particularly the
> "difftime" link to obtain intervals.
>
> 5. ?ifelse  for vectorized conditionals.
>
> Also, you might want to explain the context of what you are trying to
> do. I strongly suspect you shouldn't be doing it at all, but that is
> just a guess.
>
> Be sure to cc your reply to the list, not just to me.
>
> Cheers,
> Bert
>
>
> Bert Gunter
>
> "The trouble with having an open mind is that people keep coming along
> and sticking things into it."
> -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip
)
>
>
> On Fri, Jun 2, 2017 at 8:49 PM, Val <valkremk at gmail.com> wrote:
>> Hi all,
>>
>> I have a data set with time interval and depending on the interval I
want
>> to create 5 more variables . Sample data below
>>
>> obs,   Start,   End
>> 1,2/1/2015,  1/1/2017
>> 2,4/11/2010, 1/1/2011
>> 3,1/4/2006,  5/3/2007
>> 4,10/1/2007, 1/1/2008
>> 5,6/1/2011,  1/1/2012
>> 6,10/15/2004,12/1/2004
>>
>> First, I want get  interval between the start date and end dates
>> (End-start).
>>
>> obs,  Start , end, datediff
>> 1,2/1/2015,  1/1/2017, 700
>> 2,4/11/2010, 1/1/2011, 265
>> 3,1/4/2006,  5/3/2007, 484
>> 4,10/1/2007, 1/1/2008, 92
>> 5,6/1/2011,  1/1/2012, 214
>> 6,10/15/2004,12/1/2004,47
>>
>> Second. I want create 5 more variables  t1, t2, t3, t4 and  t5
>> The value of each variable is defined as follows
>> if datediff <   100 then  t1=1,  t2=t3=t4=t5=-1.
>> if datediff >= 100 and  < 200 then  t1=0, t2=1,t3=t4=t5=-1,
>> if datediff >= 200 and  < 300 then  t1=0, t2=0,t3=1,t4=t5=-1,
>> if datediff >= 300 and  < 400 then  t1=0, t2=0,t3=0,t4=1,t5=-1,
>> if datediff >= 400 and  < 500 then  t1=0, t2=0,t3=0,t4=0,t5=1,
>> if datediff >= 500 then  t1=0, t2=0,t3=0,t4=0,t5=0
>>
>> The complete out put looks like as follow.
>> obs, start,         end,    datediff,   t1, t2, t3, t4, t5
>> 1,    2/1/2015,   1/1/2017,    700, 0,  0,  0,  0,  0
>> 2,  4/11/2010,   1/1/2011,    265, 0,  0,  1, -1,  -1
>> 3,    1/4/2006,   5/3/2007,    484, 0,  0,  0, 0,   1
>> 4,   10/1/2007,  1/1/2008,      92, 1, -1, -1,-1,  -1
>> 5 ,    6/1/2011,    1/1/2012,  214,  0,  0,  1,-1,  -1
>> 6, 10/15/2004, 12/1/2004,     47, 1, -1, -1, -1, -1
>>
>> Thank you.
>>
>>        [[alternative HTML version deleted]]
>>
>> ______________________________________________
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>> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.

--
Peter Dalgaard, Professor,
Center for Statistics, Copenhagen Business School
Solbjerg Plads 3, 2000 Frederiksberg, Denmark
Phone: (+45)38153501
Office: A 4.23
Email: pd.mes at cbs.dk  Priv: PDalgd at gmail.com