Hi,
This relates to my earlier question on nested if statements
This one uses the auto file ..
I classify cars into 25 groups based on quintiles of mpg and length. First I
form quintiles of mpg then for each of those I form quintiles of length. Now
I append another car to the dataset say
car mpg length
maruti 50 125
How can I allocate this car to the appropriate group? (where group is a
combination of quintile number of mpg (mc) and weight(bm))
below is my code for generating the quintiles and calculating the maximum
and minimum values for the two variables mpg and length.
**************stata code************
sysuse auto,clear
keep make mpg length
* create quintiles of mpg
sort mpg
xtile mc=mpg,nq(5)
* for each quintile of mpg create quintiles of length
gen bm=.
levels mc, local(levels)
foreach i of local levels {
xtile bm_`i'=length if mc==`i',nq(5)
replace bm=bm_`i' if mc==`i'
drop bm_`i'
compress
}
* create the group as a combination of mc and bm
* a represents the group (looks like 11,12,13 etc)
tostring bm mc,replace
gen a=mc+bm
list in 1/10
levels a,local(levels)
foreach i of local levels {
egen m_max`i'=max(mpg) if a=="`i'"
egen m_min`i'=min(mpg) if a=="`i'"
egen b_max`i'=max(length) if a=="`i'"
egen b_min`i'=min(length) if a=="`i'"
replace m_max`i'=m_max`i'[_n-1] if m_max`i'>=.
replace m_min`i'=m_min`i'[_n-1] if m_min`i'>=.
replace b_max`i'=b_max`i'[_n-1] if b_max`i'>=.
replace b_min`i'=b_min`i'[_n-1] if b_min`i'>=.
}
levels a,local(levels)
foreach i of local levels {
replace m_max`i'=m_max`i'[_N]
replace m_min`i'=m_min`i'[_N]
replace b_max`i'=b_max`i'[_N]
replace b_min`i'=b_min`i'[_N]
}
* append the new company here
* fillin the max values for mpg and length here
levels a,local(levels)
foreach i of local levels {
replace m_max`i'=m_max`i'[1]
replace b_max`i'=b_max`i'[1]
replace m_min`i'=m_min`i'[1]
replace b_min`i'=b_min`i'[1]
}
* get the appropriate mc and bm if mc & bm==.
*******end code**********
I figure that the allocate will involve multiple ifs but I am not sure how
to code it..
Any help appreciated
Thanks very much
rajesh
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