This can be done more directly without any loops or
multiple new variables.
Generate the cumulative rainfall
. gen curain = sum(rain)
The rain in the previous 28 days is then
. gen prev28 = curain[_n-1] - curain[_n-29]
subject to details about the precise definition.
I learned this trick from Michael Blasnik.
Nick
[email protected]
Steven Proud
One way of doing this would be with a loop
so, could:
tsset date
local i=1
while `i'<=84 {
gen l`i'rainfall=l`i'.rainfall
local i=`i'+1
}
gen lag28rainfall=rsum(l1rainfall-l28rainfall)
gen lag84rainfall=rsum(l1rainfall-l84rainfall)
drop l1rainfall-l84rainfall
gen rain=0
replace rain=1 if rainfall>0
local i=1
while `i'<=84 {
gen l`i'rain=l`i'.rain
local i=`i'+1
}
gen lag28rain=rsum(l1rain-l28rain)
gen lag84rain=rsum(l1rain-l84rain)
drop l1rain-l84rain
I think that should work
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