I stopped at this line. There is a typo there
somewhere, as the code is illegal:
by t abs_charge:egen npos=count if charge>0
Nick
[email protected]
Sergiy Radyakin
> you will get a dozen of ways to do this more efficiently in
> several minutes,
> but here is a straightforward way:
>
> Assume your data is:
> +------------+
> | t charge |
> |------------|
> 1. | 1 10 |
> 2. | 2 20 |
> 3. | 2 20 |
> 4. | 3 30 |
> 5. | 3 20 |
> |------------|
> 6. | 3 -30 |
> 7. | 3 -30 |
> 8. | 4 10 |
> 9. | 4 20 |
> 10. | 4 30 |
> |------------|
> 11. | 4 40 |
> 12. | 5 10 |
> 13. | 5 20 |
> 14. | 5 -10 |
> 15. | 5 -10 |
> |------------|
> 16. | 5 10 |
> 17. | 5 10 |
> 18. | 5 20 |
> 19. | 5 10 |
> 20. | 5 10 |
> |------------|
> 21. | 5 10 |
> 22. | 5 -10 |
> 23. | 5 20 |
> 24. | 5 -20 |
> +------------+
>
>
> Then
>
>
>
> gen abs_charge=abs(charge)
> sort t abs_charge
> by t abs_charge:egen npos=count if charge>0
>
> gen posit=1 if charge>0
> gen negat=1 if charge<0
>
> by t abs_charge:egen npos=count(posit)
> by t abs_charge:egen nneg=count(negat)
>
> by t abs_charge:gen ndel=npos*(npos<nneg)+nneg*(nneg<npos)
>
> by t abs_charge:drop if _n<ndel | _n>_N-ndel
>
>
> Or something similar? change t as appropriate to define a group.
sara borelli
> > This is an exctract of my data:
> >
> > personid charge proc date
> > 1000124 +13 80048 6/6/2001
> > 1000124 +13 80076 6/6/2001
> > ...
> > 1000124 +13 80048 6/7/2001
> > 1000124 +13 80076 6/7/2001
> > ...
> > 1000124 -13 80048 6/7/2001
> > 1000124 -13 80076 6/7/2001
> > ...
> > 1000124 +13 80048 6/8/2001
> > ...
> > 1000124 +13 80048 6/9/2001
> > ...
> > 1000124 +13 81001 6/11/2001
> > ...
> > 1000124 +13 80048 6/11/2001
> > 1000124 +13 80048 6/12/2001
> >
> > where the dots indicate that other values for the same
> > personid are in between. I need to eliminate the
> > negative charges AND their positive counterpart with
> > the same proc and date. Thus, for example I need to
> > eliminate the negative
> > -13 80048 6/7/2001
> > AND its positive counterpart with the same proc and
> > date:
> > +13 80048 6/7/2001,
> > and so on.
> > I should find a way to construct an algorithm that
> > identifies and eliminates the negatives AND their
> > poistive counterpart with he same date and procedure,
> > but I cannot figure that out.
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