Re: re: re:st: Creating variable based on time reference (Out of office)

["Sarah Tougher" <Sarah.Tougher@lshtm.ac.uk>]

I am out of the office until November 7th. I have intermittent access to email, but will try to return your message as soon as possible. 

>>> Nick Cox <njcoxstata@gmail.com> 10/20/11 08:59 >>>

Another way to do it is

gen responsetime = cond(delta < 2, 1, cond(delta < 6, 2, 3))

with perhaps different inequalities <= and/or constants depending on
exactly "between" and "within" mean.

My personal bias against -irecode()- is that not only do I have to
look up the syntax every time, I also have to rediscover exactly what
happens with boundary cases and then document that as a part of any
respectable .do file. With -cond(,,)- my inequalities are always
explicit in the code. Conversely, the case against -cond(,,,)- is that
some find it too messy for multiple branches.

The code above is not smart about missings.

Nick

On Thu, Oct 20, 2011 at 3:42 AM, Christopher Baum <kit.baum@bc.edu> wrote:
> <.>
> To get the 'response time' categorical variable requested, the irecode() fu=
> nction is handy:
>
> bys group (datesubmitted): g delta =3D datesubmitted - datesubmitted[1]
> g responsetime = 1 + irecode(delta, 1, 5)
>
> . l
>
>    +-------------------------------------------------+
>    |   datesub   group   datesu~d   delta   respon~e |
>    |-------------------------------------------------|
>  1. | 10/1/2011       1      18901       0          1 |
>  2. | 10/9/2011       1      18909       8          3 |
>  3. |  8/1/2011       2      18840       0          1 |
>  4. |  8/2/2011       2      18841       1          1 |
>  5. |  8/5/2011       2      18844       4          2 |
>    +-------------------------------------------------+
>

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