Drop variables based on position

[John Razer]

Hi,

I would like to know how I could drop all variables placed after a position, e.g. the 6th variable/column. How can I do this?

Thanks in advance,
John

[Clyde Schechter]

Here's an illustration of how to do it with the auto.dta.

sysuse auto, clear

unab all_vars: _all
local nvars: word count `all_vars'

forvalues i = 7/`nvars' {
    drop `:word `i' of `all_vars''
}

Note: This code relies on local macros. Consequently it cannot be run line-by-line or in chunks. You must run it without interruption from start to finish.

[Nick Cox]

Here's another way to do it using findname from the Stata Journal.

sysuse auto, clear


findname, columns(1/6)
keep `r(varlist)'