install.packages('doMC')
library(doMC)
registerDoMC()
foreach(i=1:3) %dopar% sqrt(i)

getDoParWorkers()

#Parallel
x <- iris[which(iris[,5] != "setosa"), c(1,5)]
trials <- 10000
ptime <- system.time({
      r <- foreach(icount(trials), .combine=cbind) %dopar% {
      ind <- sample(100, 100, replace=TRUE)
      result1 <- glm(x[ind,2]~x[ind,1], family=binomial(logit))
      coefficients(result1)
  }
})[3]

ptime

#Serial
stime <- system.time({
    r <- foreach(icount(trials), .combine=cbind) %do% {
    ind <- sample(100, 100, replace=TRUE)
    result1 <- glm(x[ind,2]~x[ind,1], family=binomial(logit))
    coefficients(result1)
  }
})[3]
stime