[R] matching by gender and age

[David Winsemius]

On Jun 3, 2011, at 1:37 PM, 1Rnwb wrote:

> Thanks, for pointing out the package e1071, the example for  
> matchControls is
> exactly what I am looking for, however how can I add additional  
> factors to
> match for.
> library(e1071)
> Age.case <- 40 + 5 * rnorm(50)
> Age.cont <- 45 + 10 * rnorm(150)
> Age <- c(Age.case, Age.cont)
>
> Sex.case <- sample(c("M", "F"), 50, prob = c(.4, .6), replace = TRUE)
> Sex.cont <- sample(c("M", "F"), 150, prob = c(.6, .4), replace = TRUE)
> Sex <- as.factor(c(Sex.case, Sex.cont))
>
> casecont <- as.factor(c(rep("case", 50), rep("cont", 150)))
> risk.case<-sample(c("H", "M", "L"), 50, prob = c(.4,.4, .2), replace  
> = TRUE)
> risk.cont<-sample(c("H", "M", "L"), 150, prob = c(.3,.3, .4),  
> replace =
> TRUE)
> risk<-as.factor(c(risk.case, risk.cont))
>
>
> ## now look at the group properties:
> boxplot(Age ~ casecont)
> barplot(table(Sex, casecont), beside = TRUE)
> barplot(table(Sex, risk), beside = TRUE)
>
> m <- matchControls(casecont ~ Sex + Age+risk)

It runs on my device. What is the question? Are you getting an error?

-- 

David Winsemius, MD
West Hartford, CT