[R] Speeding nested loops up

[Jim Holtman]

anytime my code starts to take more than a couple of minutes to run what might look like a simple set of commands, I use Rprof to see where the time goes.  Run this on your script and you might get some insight into the problem area.  If it ran for an hour, I would defintely take a deep dive into it.

Sent from my iPad

On Aug 17, 2011, at 20:14, mark_horo <markknightnz at yahoo.co.nz> wrote:

> Hi I'm trying to speed my loop up. Any Suggestions?? At the moment it takes a
> few days to run.
> 
> THE CODE
> ---------------------------------------------------------------------------------------------------
>    for(i in 1:11) {
>        for (j in 3:12) {
>            for (k in 1:273107) {                    
>                        y[k,1] <- x[i,j,k]
>                        print(y)
>                                Rainfall_dataset <- read.table("1km_grid_nzmg.csv", 
>                                header=TRUE, sep=",", na.strings="NA", dec=".", strip.white=TRUE)    
> 
>                                t <- Rainfall_dataset
>                                print(t)
>                                
>                                p<-cbind(t,y)
>                                #y<-cbind(t,y)
>                                #print(y)            
>            }
>                        # This where you write out array y to a csv file
>                        # Save output as a csv file    
>                        site <- paste("site",i,"-",j)
> 
>                            csvfile <- paste(site,sep=".","csv"); print(csvfile)
>                            path<- paste("c:/Data/",csvfile)
>                            print(path)
>                            write.csv(p,file=path, row.names = TRUE)        
>        }
>    }
> 
> --
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