[R] Speeding things up

[Benjamin Dickgiesser]

Thanks for your answers, your help is highly appreciated!

On 1/8/07, Zoltan Kmetty <zkmetty at gmail.com> wrote:
> Hi Benjamin!
>
>
> ##TRY THIS: THIS MAYBE MUCH FASTER, BECAUSE ONLY WORK WITH THE IMPORTANAT
> ROWS - HOPE NO ERROR IN IT:D
>
> puffer1 <- as.matrix(sdata$value)
> puffer2 <- rbind(as.matrix(puffer1[2:nrow(puffer1),1]),0)
>
> speedy <- puffer1 > puffer2
> speedy <- (as.matrix(which(puffer1==TRUE)))+1
> sdata$ddtd[]=0
>
> for(cnt in 1:nrow(speedy))
>        {
>
> sdata$ddtd[speedy[cnt,1]] <- sdata$ddtd[(speedy[cnt,1]) - 1] +
> sdata$value[(speedy[cnt,1]) - 1] -sdata$value[speedy[cnt,1]]
>        }
>        return(sdata)
>
>
>
>
> #Zoltan
>
>
>
> 2007/1/8, Benjamin Dickgiesser <dickgiesser at gmail.com>:
> >
> > Hi,
> >
> > is it possible to do this operation faster? I am going over 35k data
> > entries and this takes quite some time.
> >
> >        for(cnt in 2:length(sdata$date))
> >        {
> >
> >                if(sdata$value[cnt] < sdata$value[cnt - 1])     {
> >                        sdata$ddtd[cnt] <- sdata$ddtd[cnt - 1] +
> sdata$value[cnt - 1] -
> > sdata$value[cnt]
> >                }
> >                else sdata$ddtd[cnt] <- 0
> >
> >        }
> >        return(sdata)
> >
> > Thank you,
> > Benjamin
> >
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>
>