On Apr 10, 2012, at 11:53 AM, Steve Lavrenz wrote:

Albyn,

Thanks for your help. This however, still assumes that I have to define an array of length 10. Is there a way that I can construct this so that my array is exactly as long as the number of spots I need to reach my threshold
value?

> seq(0,100, by=5)
[1] 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100


Thanks,

-Steve

-----Original Message-----
From: Albyn Jones [mailto:jo...@reed.edu]
Sent: Tuesday, April 10, 2012 11:46 AM
To: Steve Lavrenz
Cc: r-help@r-project.org
Subject: Re: [R] Creating a loop with an indefinite end term

Here are a couple of constructions that work.

albyn
===========================================

num <- rep(0,10)
for (i in 2:10)   {
     num[i] <- num[i-1] + 5
     if(num[i] > 20) break
}
num
[1]  0  5 10 15 20 25  0  0  0  0

or

num <- rep(0,10)
done <- FALSE
i <- 2
while(!done){
    num[i] <- num[i-1] + 5
    if(num[i] > 20) done <- TRUE
    i <- i + 1
}
num
[1]  0  5 10 15 20 25  0  0  0  0


On Tue, Apr 10, 2012 at 10:48:34AM -0400, Steve Lavrenz wrote:
Everyone,

I'm very new to R, especially when it comes to loops and functions, so
please bear with me if this is an elementary question. I cannot seem
to figure out how to construct a loop which runs a function until a
certain value is computed. For example, say I have the following:

num = numeric (10)
num [1] = 0
for (i in 2:10)   {
     num [i] = num [i-1] + 5
}

This adds 5 to the preceding spot of a vector of length 10 to get the
value in the current spot. However, say I don't just want to run this
for 10 spots; rather I want to run it until a certain value (say, 100) is
computed.
How I construct my loop to do this?

Thanks!


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--
Albyn Jones
Reed College
jo...@reed.edu

______________________________________________
R-help@r-project.org mailing list
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.

David Winsemius, MD
West Hartford, CT

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and provide commented, minimal, self-contained, reproducible code.

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