Re: st: imputing dates into a string date

["Joseph Coveney" <stajc2@gmail.com>]

Tim Evans wrote:

Some time ago I had a problem with imputing dates into a string variable where
the date took the form:

XX/01/2012

In the thread below a solution was provided which worked great, however, I now
have data takes the form:

/01/2012

To this, I would like to impute a day of "1", but having tried to amend the
original code below 

g dx_clean = subinstr(dx, "XX", "01", 1)

to 

g dx_clean = subinstr(dx, "", "01", 1)

The result is that I return the same value i.e. 
XX/01/2012

Does anyone have a suggestion of how I can handle this please?

--------------------------------------------------------------------------------

If you've got missing elements other than just the day, it might be better to
use -split-, and impute the days, months and years separately with their
different defaults.  You can then re-assemble the elements with simple string
concatenation (or convert the imputed dates to a Stata date).

Joseph Coveney

. version 12.1

. 
. clear *

. set more off

. 
. input str10 dx

             dx
  1. "01//2001"
  2. "/01/2001"
  3. "01/01/"
  4. end

. 
. split dx, generate(d_) parse(/)
variables created as string: 
d_1  d_2  d_3

. replace d_1 = "15" if missing(d_1) // Missing days as approx. midmonth
(1 real change made)

. replace d_2 = "06" if missing(d_2) // Missing months as approx. midyear
(1 real change made)

. replace d_3 = "2012" if missing(d_3) // Missing year as most recent full year
(1 real change made)

. 
. generate int imputed_dt = date(d_3 + d_2 + d_1, "YMD")

. format imputed_dt %tdCCYY-NN-DD

. 
. generate str10 clean_dx = d_1 + "/" + d_2 + "/" + d_3

. list dx clean_dx imputed_dt, noobs abbreviate(20)

  +------------------------------------+
  |       dx     clean_dx   imputed_dt |
  |------------------------------------|
  | 01//2001   01/06/2001   2001-06-01 |
  | /01/2001   15/01/2001   2001-01-15 |
  |   01/01/   01/01/2012   2012-01-01 |
  +------------------------------------+

. 
. exit

end of do-file

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