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RE: st: Data management
From
Nick Cox <[email protected]>
To
"'[email protected]'" <[email protected]>
Subject
RE: st: Data management
Date
Thu, 21 Oct 2010 11:52:19 +0100
Chris's approach is good, with the addition that the SD can be missing as well as zero; such observations are presumably of no interest either.
He is also correct that there are other ways to do it, which follow from the principles explained in
FAQ . . . . . . Listing observations in a group that differ on a variable
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . N. J. Cox
11/01 How do I list observations in a group that differ
on a variable?
http://www.stata.com/support/faqs/data/diff.html
So, for example, consider
bysort hhn (rentaltype) : keep if rentaltype[1] != rentaltype[_N]
Nick
[email protected]
Chris Parker
One option (I'm sure more concise options will follow) is:
bysort hhn: egen hasboth=sd(rentaltype)
drop if hasboth==0
This removes any observations where there is no variation in the
rental type across the household.
Jeetendra Aryal
> I have a big data set which is as follows:
> HHN PN Rental type
> 1 1 1
> 1 2 0
> 1 3 0
> 2 1 1
> 2 2 1
> 3 1 1
> 3 2 0
> 3 3 1
> 4 1 1
> 4 2 1
> 4 3 1
> 5 1 0
> 5 2 1
> 5 3 1
>
> Now the question is: Each household has more than one plot of land. The household can use it or rent it out or both. I want to keep only those households which have both rental types. For example, in the above dataset I want to keep only household number 1, 3 and 5. Is there any way that I can do it easily, rather than doing manually?
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