Michael,
what do you mean by "don't show"? -duplicates tag- generates a
variable representing the number of _duplicates_. It is equal to one
in your example, meaning one duplicate:
. list foreign headroom trunk dup if trunk==8 & head==2
+----------------------------------------+
| foreign headroom trunk dup_ad~d |
|----------------------------------------|
20. | Domestic 2.0 8 1 |
57. | Foreign 2.0 8 1 |
+----------------------------------------+
. duplicates report headroom trunk if trunk==8 & head==2
Duplicates in terms of headroom trunk
--------------------------------------
copies | observations surplus
----------+---------------------------
2 | 2 1
--------------------------------------
If this is not what you want, please include more detail of what it is
that you want to achieve. In case you want to generate a running
counter for duplicates among your variables, try this:
. bysort head trunk: gen obsno = _n
. list foreign headroom trunk dup obsno if trunk==8
+------------------------------------------------+
| foreign headroom trunk dup_ad~d obsno |
|------------------------------------------------|
3. | Domestic 1.5 8 0 1 |
7. | Domestic 2.0 8 1 1 |
8. | Foreign 2.0 8 1 2 |
19. | Foreign 2.5 8 1 1 |
20. | Foreign 2.5 8 1 2 |
+------------------------------------------------+
Hopes this helps,
Eva
2008/9/3 Michael McCulloch <[email protected]>:
> Hello,
> I'm testing -duplicates tag-, and puzzled as to why it won't show the two
> observations where headroom==2.0 and trunk==8.
>
> clear
> sysuse auto
> list foreign headroom trunk if trunk==8
> duplicates tag headroom trunk, generate(dup_admission_id)
>
> --
>
> Best wishes,
> Michael McCulloch
>
>
>
> Pine Street Foundation
> 124 Pine St., San Anselmo, CA 94960-2674
> Tel: (415) 407-1357
> Fax: (415) 485-1065
> [email protected]
> www.pinestreetfoundation.org
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