How to choose first character observation based on time

[msyteriouspages]

Hi there! I’m trying to create indicator values using two variables. I would like to get the first observation (of interest) according to the first time that observation occurs. For example, this is the dataset I have:

ID Action DateTime
1 Started 01AUG2021:15:39:01.000
1 Test A 01AUG2021:15:41:01.000
1 Check 01AUG2021:16:32:01.000
1 Test A 01AUG2021:16:39:01.000
1 Test B 01AUG2021:17:55:01.000

What I want:

I want to create an indicator that records the first time Test A happens

ID Action DateTime Test_A
1 Started 01AUG2021:15:39:01.000 0
1 Test A 01AUG2021:15:41:01.000 1
1 Check 01AUG2021:16:32:01.000 0
1 Test A 01AUG2021:16:39:01.000 0
1 Test B 01AUG2021:17:55:01.000 0


I tried multiple things, I tried to create a condition using minimum date & also by the first occurrence but nothing worked. I’d greatly appreciate any help. Thank you

[Reeza · Accepted solution]

data want;
set have;
by ID;

retain first_found;
flag = 0;
if first.id then first_found=0;

if action = 'Test A' and first_found = 0 then do;
flag=1;
first_found=1;
end;

run;

Use another flag that is retained that checks if the first record was ever found.

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@msyteriouspages wrote:
Hi there! I’m trying to create indicator values using two variables. I would like to get the first observation (of interest) according to the first time that observation occurs. For example, this is the dataset I have:

ID Action DateTime
1 Started 01AUG2021:15:39:01.000
1 Test A 01AUG2021:15:41:01.000
1 Check 01AUG2021:16:32:01.000
1 Test A 01AUG2021:16:39:01.000
1 Test B 01AUG2021:17:55:01.000

What I want:

I want to create an indicator that records the first time Test A happens

ID Action DateTime Test_A
1 Started 01AUG2021:15:39:01.000 0
1 Test A 01AUG2021:15:41:01.000 1
1 Check 01AUG2021:16:32:01.000 0
1 Test A 01AUG2021:16:39:01.000 0
1 Test B 01AUG2021:17:55:01.000 0


I tried multiple things, I tried to create a condition using minimum date & also by the first occurrence but nothing worked. I’d greatly appreciate any help. Thank you

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