通过将变量除以Stata中的IQR来创建变量
如何通过将变量除以IQR来创建变量?我已经做了很长一段路如下 示例数据和代码如下所示:通过将变量除以Stata中的IQR来创建变量,stata,Stata,如何通过将变量除以IQR来创建变量?我已经做了很长一段路如下 示例数据和代码如下所示: use http://www.ats.ucla.edu/stat/stata/notes/hsb2, clear foreach var of varlist read-socst { egen `var'75 = pctile(`var'), p(75) egen `var'25 = pctile(`var'), p(25) gen `var'q =`var'75 - `var'25
use http://www.ats.ucla.edu/stat/stata/notes/hsb2, clear
foreach var of varlist read-socst {
egen `var'75 = pctile(`var'), p(75)
egen `var'25 = pctile(`var'), p(25)
gen `var'q =`var'75 - `var'25
drop `var'75 `var'25
}
gen readI = read/readq
gen sciI = science/scienceq
最简单的方法就是直接使用
总结结果:
sysuse auto, clear
quietly foreach v of var price-foreign {
su `v', detail
gen `v'q = `v' / (r(p75) - r(p25))
}
如果这意味着为每个原始变量创建新变量,只是为了将四分位数或IQR保持为重复常量,那么egen
路线就太过了。但是,当您希望按组执行此操作时,egen
就有了自己的功能:
bysort foreign: egen mpg_upq = pctile(mpg), p(75)
by foreign: egen mpg_loq = pctile(mpg), p(25)
gen mpg_Q = mpg / (mpg_upq - mpg_loq)
请注意,IQR可以为0,对于指标变量,IQR通常为0