Hi,

I was trying to gather/combine the results returned from the mclapply function. This is how I do it if only one data object is returned:

#===== This works fine =======

library(multicore)

frandom1 <- function(iter,var1 = 3,var2 =2){ 
    mat <- matrix(rnorm(var1*var2),nrow=var1,ncol=var2)
    return(mat)    
}
N <- 3

### OK
temp1 <- mclapply(1:N,frandom1,mc.cores=2)
result1 <- do.call(rbind,temp1)
print(result1)

#========================

Now, I want to return more than one object from my function and I am not sure how best to combine the values returned. My current code is:

#======= ??? =====
frandom2 <- function(iter,var1 = 3,var2 =2){ 
    mat <- matrix(rnorm(var1*var2),nrow=var1,ncol=var2)
    vect1 <- sample(1:1000,var1)
    return(list(mat,vect1))    
}

temp2 <- mclapply(1:N,frandom2,mc.cores=2)


#### Combining returned values????
result2 <- result3 <- c()
for(k in 1:N){
    thismat <- temp2[[k]][[1]]
    result2 <- rbind(result2,thismat)
    
    thisvect <- temp2[[k]][[2]]
    result3 <- c(result3,thisvect)
    
}

#==============


Is there a more elegant way of combining these values (as in the top example)? Although this works, for a large value of N ( N > 500,000), running a loop would be very expensive. 


Any help would be appreciated!

thanks!

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