How Can I Quickly Find an Observation with Specific ID in Stata?

[smith Jason]

Hi, I have a small dataset for the purpose of demonstration below,
clear
input str80 id byte male
000001 0
000001 0
000001 0
000001 0
000002 0
000002 0
000002 0
000002 0
000003 0
000003 0
000003 0
000003 0
000004 1
000004 1
000004 1
end
I just try to make sure that I can use Stata code to quickly identify an observation with specific ID. For example, I want to find where the observations with the ID of "000004" are.
Can someone show me how to do this in Stata code?
Thank you!

[Mike Lacy]

If by "identify," you mean "find out the observation numbers(s)," you could do:

list id if (id == 4) // obs numbers listed on the left

If you want those observation numbers to go into an object you can use for some other purpose, you could do:

gen obs = _n
tab obs if (id == 4), matrow(A)
mat list A  
//  Another possibility for making the list of observation numbers manipulable:
levelsof obs if (id == 4), local(pos)
di "`pos'"

[smith Jason]

Thank you!

[Leonardo Guizzetti]

You can be more succinct if you can ensure that any observations matching the filter criterion exists as a contiguous block of observations in your dataset (or perhaps don't exist at all). For example, in pseudo code:

// May wish to sort data first by some sensible way to group like observations, but only needed for ranges of observations
gen `c(obs_t)' obs = _n
summ myvar if mycond , meanonly

Following this, summarize returns to local macros to r(min) and r(max) the first and last observation number matching the condition, respectively.

[smith Jason]

Thank you!