What learning algorithms are "embarrassingly parallel?" I'll kick it off with the obvious example from the foreach documentation:
rf <- foreach(ntree = rep(250, 4), .combine = combine, .packages = "randomForest") %dopar%
randomForest(x, y, ntree = ntree)
What else is out there that can be easily parallelized with foreach?
Bagging is embarrassingly parallel:
bagging<-function(training,testing,length_divisor=4,iterations=1000)
{
predictions<-foreach(m=1:iterations,.combine=cbind) %do% {
training_positions <- sample(nrow(training), size=floor((nrow(training)/length_divisor)))
train_pos<-1:nrow(training) %in% training_positions
lm_fit<-lm(y~x1+x2+x3,data=training[train_pos,])
predict(lm_fit,newdata=testing)
}
rowMeans(predictions)
}