Create new variable based off of previous values

[lalaktgrau]

Hi,

I'd like to create a variable that =1 when:
moving starts (first instance of moving=1) and continues being 1 until disease has continued for 3 minutes.Then, it becomes zero again.
Therefore, it only captures the onset of moving and the first 3 minutes of disease.

data WORK.CLASS;
infile datalines truncover;
input Name:$8. moving disease datetime;
informat datetime datetime20.;
format datetime datetime20.;
datalines;
Alfred 0 0 04MAR14:23:55:00
Alfred 0 0 04MAR14:23:56:00
Alfred 1 0 04MAR14:23:57:00
Alfred 1 0 04MAR14:23:58:00
Alfred 1 0 04MAR14:23:59:00
Alfred 1 1 05MAR14:00:00:00
Alfred 1 1 05MAR14:00:01:00
Alfred 1 1 05MAR14:00:02:00
Alfred 1 1 05MAR14:00:03:00
Alfred 1 1 05MAR14:00:04:00
mary 0 0 04MAR14:23:55:00
mary 0 0 04MAR14:23:56:00
mary 0 0 04MAR14:23:57:00
mary 0 0 04MAR14:23:58:00
mary 0 0 04MAR14:23:59:00
mary 1 0 05MAR14:00:00:00
mary 1 1 05MAR14:00:01:00
mary 1 1 05MAR14:00:02:00
mary 1 1 05MAR14:00:03:00
mary 1 1 05MAR14:00:04:00;

So if the variable was created properly, it would look like this:

Alfred 0 0 04MAR14:23:55:00 0 
Alfred 0 0 04MAR14:23:56:00 0 
Alfred 1 0 04MAR14:23:57:00 1 
Alfred 1 0 04MAR14:23:58:00 1 
Alfred 1 0 04MAR14:23:59:00 1 
Alfred 1 1 04MAR14:00:00:00 1 
Alfred 1 1 04MAR14:01:01:00 1 
Alfred 1 1 04MAR14:01:02:00 1 
Alfred 1 1 04MAR14:01:03:00 0 
Alfred 1 1 04MAR14:01:04:00 0

[ChrisNZ]

1.Why is everything 04MAR14 even after midnight?

2.Why is Mary excluded when it matches (first instance of moving=1) and continues being 1 until disease has continued for 3 minutes

[lalaktgrau]

It was just an example of times. This isn't my actual data, though it is very similar. 

I just gave Alfred as a sample. 

[mkeintz]

The sample may be synthetic, which is fine, but it doesn't even follow your description.  Specifically, it is not in chronological order.  This does not help us help you.

[lalaktgrau]

oh! Sorry. I had changed the datepart for the creation of another variable. I edited it! It should be good now!

[mkeintz · Accepted solution]

Now your data series skips from midnight to 1 hour after midnight.  Is that intentional?   I've changed them from 01:01:00, 01:02:00  to 00:01:00, 00:02:00, etc:

data WORK.CLASS;
infile datalines truncover;
input Name:$8. moving disease datetime;
informat datetime datetime20.;
format datetime datetime20.;
datalines;
Alfred 0 0 04MAR14:23:55:00
Alfred 0 0 04MAR14:23:56:00
Alfred 1 0 04MAR14:23:57:00
Alfred 1 0 04MAR14:23:58:00
Alfred 1 0 04MAR14:23:59:00
Alfred 1 1 05MAR14:00:00:00
Alfred 1 1 05MAR14:00:01:00
Alfred 1 1 05MAR14:00:02:00
Alfred 1 1 05MAR14:00:03:00
Alfred 1 1 05MAR14:00:04:00
mary 0 0 04MAR14:23:55:00
mary 0 0 04MAR14:23:56:00
mary 0 0 04MAR14:23:57:00
mary 0 0 04MAR14:23:58:00
mary 0 0 04MAR14:23:59:00
mary 1 0 05MAR14:00:00:00
mary 1 1 05MAR14:00:01:00
mary 1 1 05MAR14:00:02:00
mary 1 1 05MAR14:00:03:00
mary 1 1 05MAR14:00:04:00
run;


data want (drop=dis_dt);
  set class;
  by name;
  format dis_dt datetime20.;
  retain dummy dis_dt;
  if first.name then do;
     dummy=0;
     dis_dt=constant('bigint');  /* Make a dummy date way in the future*/
  end;
  if moving=1 then dummy=1;
  if dif(disease)=1 then dis_dt=datetime;
  if datetime>dis_dt+'00:03:00't then dummy=0; /*Set actual disease date when encountered*/
run;
proc print;run;

 This program assumes:

1. moving always starts no later than disease
2. Only moving start or disease starts they never go back to zero.

[lalaktgrau]

This is great, thank you!

Quick question: Is there a way to include a DO UNTIL loop that  would stop processing (that day for that person) after we reach the first consecutive 3 minutes of disease?

In other words, if later that night disease becomes 0 and then goes back to 1--I don't want to count them.

data WORK.CLASS;
infile datalines truncover;
input Name:$8. moving disease datetime;
informat datetime datetime20.;
format datetime datetime20.;
datalines;
Alfred 0 0 04MAR14:23:55:00
Alfred 0 0 04MAR14:23:56:00
Alfred 1 0 04MAR14:23:57:00
Alfred 1 0 04MAR14:23:58:00
Alfred 1 0 04MAR14:23:59:00
Alfred 1 1 05MAR14:00:00:00
Alfred 1 1 05MAR14:00:01:00
Alfred 1 1 05MAR14:00:02:00
Alfred 1 0 05MAR14:00:03:00
Alfred 1 1 05MAR14:00:04:00
mary 0 0 04MAR14:23:55:00
mary 0 0 04MAR14:23:56:00
mary 0 0 04MAR14:23:57:00
mary 0 0 04MAR14:23:58:00
mary 0 0 04MAR14:23:59:00
mary 1 0 05MAR14:00:00:00
mary 1 1 05MAR14:00:01:00
mary 1 1 05MAR14:00:02:00
mary 1 1 05MAR14:00:03:00
mary 1 1 05MAR14:00:04:00

run;