st: Generating patterns from longitudinal data

[Scott Smith <scottsmith1183@gmail.com>]

Hello,

I am wondering if there is an efficient method of creating and
tabulating patterns from longitudinal data. For example, I have four
waves of data with a dichotomous variable. I want to create a new
variable that will have each pattern and a count of that pattern.
There are 16 possible patterns. Instead of doing this:

gen var1=.
replace var1=0000 if time1==0 & time2==0 & time3==0 & time4==0
replace var1=1111  if time1==1 & time2==1 & time3==1 & time4==1

and doing that for the remaining 14 patterns (e.g., 0001, 0011, 0111,
1010, 0101, etc), is there way of telling stata to do this and store
it in a new variable? Otherwise, I have to manually do it, and it
takes a lot of time when I start adding demographics (because I have
to repeat the code for each level of the demographic variable).

It should look like this when I tab var1 (except for all the patterns):

var1          freq.

0000         1,000
1111          1,050
0001            850

I am using stata version 11.2.

Thank you,

Scott
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