[R] How to create several variables from composite character variable

Dale Steele dale.w.steele at gmail.com
Fri Aug 17 23:32:54 CEST 2007

I'm trying to create two variables (dka and newsonset) from the
following composite character variable diagnosis:

diagnosis <- c("hypoglycemia","diabetes" ,"newonset&dka", "newonset",
"diabetes", "dka&GI", "diabetes&GI", "newonset", "dka")

I can extract the indices for dka and newonset using the following....

> grep("dka", diagnosis)
[1] 3 6 9
> grep("newonset", diagnosis)
[1] 3 4 8

How do I create

 dka      = c(0,0,1,0,0,1,0,0,1)
 newonset = c(0,0,1,1,0,0,0,1,0)

Thanks.  --Dale

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