How to get observations as a list in Stata?

问题

Stata has r() macro for values that some commands return (return list after the command).

I need similar access to x after list x if y == 1, but list returns only r(N), not values themselves.

Is it possible to get the observations as a local or global macro to refer to it in the code?

回答1:

Try levelsof command to get distinct values. It's the cat's pajamas.

回答2:

One way to save values of all observations (i.e. including repeated) is with a loop:

clear 
set more off

*----- exmple data -----

sysuse auto
keep rep78

list

*----- what you want -----

forvalues i = 1/`=_N' {
    local myvals `myvals' `=rep78[`i']'
}

display "`myvals'"

But more importantly, why do you think you need such a thing?

来源：https://stackoverflow.com/questions/27214675/how-to-get-observations-as-a-list-in-stata