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# RE: st: Code to generate dummy variable from several categorical variables?

 From "DEBORAH L. HUANG" To statalist@hsphsun2.harvard.edu Subject RE: st: Code to generate dummy variable from several categorical variables? Date Mon, 16 Jan 2012 16:46:25 -0800 (PST)

```Thank you for input and to clarify what I'm trying to do:

I'm trying to generate a dummy variable with 4 indicators; the values of the indicators are to be determined by 3 other binary variables which are not mutually exclusive. If generating a categorical variable could be done more easily that would be fine. I've already tried generating a composite categorical variable but have recoding problems as A, B and C are not mutually exclusive.

For example, possible values for binary variables A, B and C as follows:

A     B     C
1.  1     0     0
2.  1     1     0
3.  1     1     1
4.  0     1     0
5.  0     1     1
6.  0     0     1
7.  0     0     0

So I'd like to generate dummy variable abnlX, where
- abnlX1 includes all subjects where A=1
- abnlX2 includes all subjects where B=1
- abnlX3 includes all subjects where C=1

My difficulty is in figuring out how to code in order to re-categorize subjects #2, #3 and #5 into all the appropriate categories (e.g., subject #2 should count toward abnlX1 and abnlX2). Additionally, there are some missing values for any of the variables A, B or C (subject may be missing value for A but have values for B and C, etc.) but I would still like to be able to include the available values.

Hopefully my question makes more sense. Thank you!
Deborah

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