How to obtain standard deviation while using Survey data and subpopulation option

[ritupuri]

Dear 　Stata users ,　
I am using a survey dataset and trying to obtain standard deviation(for mean) after using subpop option. 　There were a thread previously, but the discussion was to obtain SD, when subpop option was not specified.(http://www.stata.com/statalist/archi.../msg00581.html). There they used the formula di sqrt(e(N) * el(e(V_srs), 1, 1)) to obtain standard devation.

However, for my analysis, I am using subpop option. 　Can anyone of the stata users please guide me if I am using the correct formula :
di sqrt(e(N) * el(e(V_srssub), 1, 1))to obtain Standard deviation .

  ** 　STATA CODE START ******
  webuse nhanes2, clear
  svy, subpop(if region==2): mean loglead
  di sqrt(e(N) * el(e(V_srssub), 1, 1))
  estat sd, srs
  ** 　STATA CODE END ******

Thank you very much for your time,
Ritu

[Steve Samuels]

The following is correct:

di sqrt(e(N_sub)*el(e(V_srssub), 1, 1))

[ritupuri]

Dear Samuels,
Thank you very much for your help.
Ritu