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
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