Re: st: How to quickly merge by the range of a third variable?

[Rafal Raciborski <rafal.raciborski@emory.edu>]

Sean,

Why not something like this?:


. use person, clear

. list

    +--------------------------+
    | personid   bday   bplace |
    |--------------------------|
 1. |        1   1950    city1 |
 2. |        2   1951    city2 |
 3. |        3   1987    city2 |
 4. |        4   1950    city3 |
 5. |        5   1975    city1 |
    +--------------------------+

. use c1951, clear

. list

    +-----------------------+
    |  city   year      pop |
    |-----------------------|
 1. | city1   1951    10250 |
 2. | city2   1951   301872 |
 3. | city3   1951    65790 |
    +-----------------------+

. use c1950, clear

. list

    +-----------------------+
    |  city   year      pop |
    |-----------------------|
 1. | city1   1950    10000 |
 2. | city2   1950   300000 |
 3. | city3   1950    65000 |
    +-----------------------+

. append using c1951

. sort city year

. list

    +-----------------------+
    |  city   year      pop |
    |-----------------------|
 1. | city1   1950    10000 |
 2. | city1   1951    10250 |
 3. | city2   1950   300000 |
 4. | city2   1951   301872 |
 5. | city3   1950    65000 |
    |-----------------------|
 6. | city3   1951    65790 |
    +-----------------------+

. save city_big, replace
file city_big.dta saved

.
. use person, clear

. rename bday year

. rename bplace city

. sort city year

. save person1, replace
file person1.dta saved

.
. merge city year using city_big

. drop if _merge==2
(3 observations deleted)

. drop _merge

. list

    +----------------------------------+
    | personid   year    city      pop |
    |----------------------------------|
 1. |        1   1950   city1    10000 |
 2. |        5   1975   city1        . |
 3. |        2   1951   city2   301872 |
 4. |        3   1987   city2        . |
 5. |        4   1950   city3    65000 |
    +----------------------------------+

.
end of do-file


If your city datasets do not have a year variable in them, you can 
easliy add it
using -forvalues-.  Assuming your city datasets are named c1950, c1951, ... ,
c2000, you can use:

forvalues i = 1950/2000 {
	use c`i', clear
	gen year = `i'
	save, replace
}

and then append and merge.

Hope this helps.

rafal


================
Rafal Raciborski
Graduate student
Department of Political Science
Emory University
301 Tarbutton Hall
1555 Dickey Drive
Atlanta, GA 30322
404-378-9826 (home)
rafal.raciborski@emory.edu
http://www.roofoos.net/


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