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# Re: st: Merging files based on name and year

 From Nick Cox To statalist@hsphsun2.harvard.edu Subject Re: st: Merging files based on name and year Date Sun, 4 Sep 2011 09:29:14 +0100

```Many ways to this. One is

egen nmissing = total(missing(score)), by(name)
egen meanscore = mean(score) if nmissing == 0, by(name)

Another is

bysort name (score) : gen meanscore = sum(score)
by name : replace meanscore = cond(missing(score[_N}), ., meanscore[_N]/_N)

Nick

On Sun, Sep 4, 2011 at 9:11 AM, Joseph Monte <hmjc66@gmail.com> wrote:
> Nick,
>
> Thanks for the help. It worked well. Unfortunately, I'm stuck at the
> final stage where I need to take the average score for each name
> conditional on a score being available for each name. Unfortunately, I
> do have missing observations.
>
> . input str1 name score
>
>            name       score
>  1. "A" 7
>  2. "A" 8
>  3. "A" .
>  4. "B" 6
>  5. "B" 7
>  6. "C" 5
>  7. end
>
> . egen meanscore = mean(score), by(name)
>
> . list
>
>     +--------------------+
>     | name   score   meanscore |
>     |--------------------|
>  1. |  A      8      7.5 |
>  2. |  A      7      7.5 |
>  3. |  A      .      7.5 |
>  4. |  B      7      6.5 |
>  5. |  B      6      6.5 |
>     |--------------------|
>  6. |  C      5        5 |
>     +--------------------+
>
> I want meanscore not to be calculated for A since there is a missing
> observation (i.e. there should be 3 blanks instead of 7.5). How do I
> get around this issue? I tried adapting the code from the link below
> but was not successful.
>
> http://www.stata.com/support/faqs/data/anyall.html
>
> Thanks,
>
> Joe
>
>
>
>
>
>
> On Thu, Aug 25, 2011 at 9:52 AM, Nick Cox <njcoxstata@gmail.com> wrote:
>> I don't think regex is the only approach here. You could consider
>> using -split-.
>>
>> A strategy here is to insert new parsing characters yourself. For
>> example suppose that ; is not used, which you can check by
>>
>> assert strpos(name, ";") == 0
>>
>> Then put ; after each terminal element such as "Inc" (there's probably
>> jargon I don't know)
>>
>> clonevar work = name
>> replace work = subinstr(work, "Inc", "Inc;", .)
>> replace work = subinstr(work, "LLC", "LLC;", .)
>> replace work = subinstr(work, "Corp", "Corp;", .)
>>
>> and so on.
>>
>> You can get all the terminal elements from your file with just
>> individual names. It is the last word (word(,-1)) of the company name.
>> You can put that into a new variable and -tab- the results.
>>
>> You may need to fix exceptions, which will be shown by the tabulation above.
>>
>> Then -split- on ; and then -reshape-.
>>
>> Sometimes a very primitive approach like this is much quicker than
>> spending hours trying to do it a cleverer way. (If someone were
>> exceptionally fluent with regular expressions that wouldn't be true.)
>>
>> When regex works it can be a spectacular solution but with many messy
>> problems it is often a very long way round.
>>
>> Nick
>>
>> On Thu, Aug 25, 2011 at 9:24 AM, Joseph Monte <hmjc66@gmail.com> wrote:
>>
>>> The file below is the master file containing names of companies and
>>> years. ABC Inc is one company, XYZ Corp is another company, PNG LLC is
>>> a third company. I have a total of 1100 different companies. As shown
>>> below, sometimes two or more companies are listed in the same field
>>> (there are a maximum of 5 companies listed in the same field). The
>>> year column has only one year for each observation. There are a total
>>> of 800 observations in this file.
>>>
>>> name                    year
>>> ABC Inc                 1986
>>> XYZ Corp                        1994
>>> ABC Inc XYZ Corp        2001
>>> PNG LLC                 2005
>>> XYZ Corp PNG LLC        2007
>>>
>>>
>>> I have a second file with data in the following format. The 1100
>>> companies are listed as shown below. YR8084 means the years 1980-1984,
>>> YR8591 means the years 1985-1991, and so on. The numbers below each
>>> year are scores assigned to each company during a certain period. For
>>> example, ABC Inc is assigned a score of 6 during 1980-1984, 7 from
>>> 1985-1991, and 9 from 2001-2004. ABC Inc is not assigned a score
>>> during other periods. Scores range from 1 to 9 and may be up to 3
>>> decimal places.
>>>
>>> name            YR8084  YR8591  YR9200  YR0104  YR0507  YR0809
>>> ABC Inc             6                7                              9
>>> XYZ Corp                                     2               5              6              6
>>> PNG LLC                              7               7              7
>>>  7                   7
>>>
>>>
>>> I want the master file to include a column with scores as shown below.
>>> For example, ABC Inc gets a score of 7 in 1986, XYZ Corp gets a score
>>> of 5 in 1994. For observations with two or more names, I want a simple
>>> average of scores. For example, for ABC Inc XYZ Corp, the score will
>>> be (9+6)/2=7.5. If a company has a year in the master file, then it
>>> definitely has a score for that year (i.e. time period) in the second
>>> file.
>>>
>>> name                    year                score
>>> ABC Inc                 1986                   7
>>> XYZ Corp                        1994                   5
>>> ABC Inc XYZ Corp        2001                  7.5
>>> PNG LLC                 2005                   7
>>> XYZ Corp PNG LLC        2007                  6.5
>>>
>>> I am using Stata 12. I expect I would need the -regexm()- command to
>>> split the company names, then -reshape- to get all company names one
>>> below the other and then -merge-. Since there are 1100 companies, I
>>> would need some kind of a loop to use the -regexm() command. I am
>>> having trouble writing the code.
>>>
>>
>> *
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>>
>
> *
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```

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