Re: st: RE: Dropping Duplicates that Aren't Exactly Duplicates

[Lisa Chavez <lchavez@law.berkeley.edu>]

It worked!   Thank you so much!    I suspected that the answer to my 
problem would be found in reshaping to wide...:::smacking forehead::

On 11/2/2011 12:44 PM, Dimitriy V. Masterov wrote:
> Lisa,
>
> I think the inelegant code below will accomplish what you want. It is
> untested and hinges on the violation variable being very clean. If the
> latter is not the case, you may want to take a look at Google Refine.
>
> /* remove leading, trailing and multiple whitespaces&  convert to
> uppercase (may not be necessary, but good habit with ) */
> replace violation=upper(trim(itrim(violation)));
>
> /* sencode is from ssc. This not necessary, but may speed sorting if
> you have lots of data */
> sencode violation, replace;
>
> /* reshape to make finding duplicates easier */
> bys id arrdate (violation): gen cause=_n;
> reshape wide violation, i(id arrdate) j(cause);
> egen all_violations=group(violation*), missing;
> sort id arrdate all_violation;
> duplicates drop id all_violations, force; // duplicate will drop all
> by the first occurrence, which will the earliest arrest because of the
> sort
>
> /* reshape back to your original format&  drop extraneous variables */
> reshape long violation, i(id arrdate) j(cause);
> drop if missing(violation);
> drop all_violations cause;
> *
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