Thank you very much Nick. This is such a parsimonious solution! As I received your email, I found out one solution, far from being parsimonious... (fyi see below)
Thanks again.
Thi Minh
use C:\Vlss\Vlss98\Data\Household\SCR09A12.DTA, clear
keep househol s9a1plot s9a1q04
rename s9a1q04 psize
for newlist plot1 plot2 plot3 plot4 plot5 : gen X=s9a1plot
drop s9a1plot
sort househol plot1 plot2 plot3 plot4 plot5
save c:\vlss\land\data2.dta, replace
foreach x of varlist plot1 plot2 plot3 plot4 plot5 {
use c:\vlss\land\data2.dta, clear
sort househol `x'
save c:\vlss\land\data2.dta, replace
use c:\vlss\land\data1.dta, clear
compress
sort househol `x'
merge househol `x' using c:\vlss\land\data2.dta
drop _m
rename psize psize`x'
save c:\vlss\land\data1.dta, replace
}
drop if riceseason==.
egen riceplottot=rsum(psizeplot1 psizeplot2 psizeplot3 psizeplot4 psizeplot5)
sort househol riceseason
save c:\vlss\land\data1.dta, replace
-----Original Message-----
From: Nick Cox [mailto:[email protected]]
Sent: 21 October 2002 18:11
To: [email protected]
Subject: st: RE: merging data
Ngo,PT (pgr)
> In one data set, I have data indicating the size (s9a1q04)
> of each plot (s9a1plot) cultivated by a household.
>
> s9a1plot s9a1q04
> 1 816
> 2 456
> 3 384
> 4 360
> 5 360
> 6 204
> 7 180
>
>
> In another data set, I have data which show which plots (5
> plots maximum, listed under the variables plot 1 to plot5)
> have been planted for each rice season (riceseason, there
> are 7 categories in total).
>
> riceseason plot1 plot2 plot3 plot4 plot5
> 1 1 3 4 5 6
> 3 1 4 5 6 .
> 6 2 3 7 . .
>
> I would like to calculate the landsize planted for each rice season.
>
> I have merge my data, and I obtain the following:
>
> l s9a1plot s9a1q04 riceseason plot1- plot5 if house==1101
>
> s9a1plot s9a1q04 riceseason plot1 plot2
> plot3 plot4 plot5
> 1 816 1 1 3 4
> 5 6
> 2 456 3 1 4 5
> 6 .
> 3 384 6 2 3 7
> . .
> 4 360 6 2 3 7
> . .
> 5 360 6 2 3 7
> . .
> 6 204 6 2 3 7
> . .
> 7 180 6 2 3 7
> . .
>
> Now, I would like to allocate for each season the landsize
> of each plot, so something like this:
>
> s9a1plot s9a1q04 riceseason plot1 plot2
> plot3 plot4 plot5
> 1 816 1 816 384 360
> 360 204
> 2 456 3 816 360 360
> 204 .
> 3 384 6 456 384 180
> . .
> (The lines below are repetitions.)
> 4 360 6 2 3 7
> . .
> 5 360 6 2 3 7
> . .
> 6 204 6 2 3 7
> . .
> 7 180 6 2 3 7
> . .
>
I'd go back one stage. Your -merge- solves one problem
but creates another.
Reading in your second data set, which presumably also
includes a -house- variable,
riceseason plot1 plot2 plot3 plot4 plot5
1 1 3 4 5 6
3 1 4 5 6 .
6 2 3 7 . .
first -reshape- to long,
. reshape long plot, i(house riceseason)
and clean up
. drop if plot == .
Then prepare for -merge-
. sort house plot
. rename plot s9a1plot
. save data2
. clear
Now in your first data set
. sort house s9a1plot
. merge house s9a1plot using data2
you should get a long data set,
and you can -collapse- or
. bysort house season : egen total = sum(s9a1q04)
Nick
[email protected]
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