R help - Jun 2006 - nested for loop restriction?

Hello,

is there a restriction for the number of loops in a nested for-loop in R?
I wrote a small function to replace water gage hights by discharge values, where
the outer loop walks through the levels of a gage time series and the inner loop
looks up the corresponding dicharge value in a vector.
It seems to work well, with the (however very annoying) restriction that the
inner loop stops after 60 steps.
I attached the function at the end of the mail, where tpframe is a 2-column time
series dataframe (date,gage hights) and pqframe is a 2-column dataframe (gage
hights, discharge).
Any kind of help appreciated,  as I am no native programmer and also quite new
to R also replies like "nice try, but there is a more convenient way in R:
...",

thanks in advance,
Ren?


p.zu.q <- function (tpframe, pqframe) {
	tp <- factor(tpframe[[2]])
	tq <- tp
	p <- pqframe[[1]]
	q <- pqframe[[2]]

	for (i in 1:length(levels(tp))) {
		pegel<-levels(tp)[i]

		for (j in 1:length(brugga.p)) {
			if (p[j] == pegel) 
				{levels(tq)[i] <- q[j]
			break
			}
		else next
		}
	next
	}

	tpq <- cbind(tpframe[[1]],as.data.frame(tp),as.data.frame(tq))
	names(tpq) <- c("date","P mm","Q m3/s")
	tpq
} 
_____________________________________________________________________
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Hi

If you do not insist on loops you can either use merge

merge(tpframe, pqframe)

or

df.new<-data.frame(date=tpframe$date, 
discharge=pqframe$discharge[match(tpframe$gage heights, pqframe$gage 
heights)])

I hope I did not do typo :-)

HTH
Petr




On 20 Jun 2006 at 14:20, Ren? Capell wrote:

Date sent:      	Tue, 20 Jun 2006 14:20:50 +0200
From:           	Ren? Capell <rene.ca at web.de>
To:             	r-help at stat.math.ethz.ch
Organization:   	http://freemail.web.de/
Subject:        	[R] nested for loop restriction?
> Hello,
> 
> is there a restriction for the number of loops in a nested for-loop in
> R? I wrote a small function to replace water gage hights by discharge
> values, where the outer loop walks through the levels of a gage time
> series and the inner loop looks up the corresponding dicharge value in
> a vector. It seems to work well, with the (however very annoying)
> restriction that the inner loop stops after 60 steps. I attached the
> function at the end of the mail, where tpframe is a 2-column time
> series dataframe (date,gage hights) and pqframe is a 2-column
> dataframe (gage hights, discharge). Any kind of help appreciated,  as
> I am no native programmer and also quite new to R also replies like
> "nice try, but there is a more convenient way in R: ...",
> 
> thanks in advance,
> Ren?
> 
> 
> p.zu.q <- function (tpframe, pqframe) {
>  tp <- factor(tpframe[[2]])
>  tq <- tp
>  p <- pqframe[[1]]
>  q <- pqframe[[2]]
> 
>  for (i in 1:length(levels(tp))) {
>   pegel<-levels(tp)[i]
> 
>   for (j in 1:length(brugga.p)) {
>    if (p[j] == pegel) 
>     {levels(tq)[i] <- q[j]
>    break
>    }
>   else next
>   }
>  next
>  }
> 
>  tpq <- cbind(tpframe[[1]],as.data.frame(tp),as.data.frame(tq))
>  names(tpq) <- c("date","P mm","Q m3/s")
>  tpq
> } 
> _____________________________________________________________________
> Der WEB.DE SmartSurfer hilft bis zu 70% Ihrer Onlinekosten zu sparen!
> 
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Petr Pikal
petr.pikal at precheza.cz