From: David Winsemius <dwinsemius_at_comcast.net>

Date: Thu, 21 Apr 2011 11:44:19 -0400

Date: Thu, 21 Apr 2011 11:44:19 -0400

On Apr 21, 2011, at 9:04 AM, Michael Dewey wrote:

> At 10:42 20/04/2011, Georgina Imberger wrote:

*>> Hi!
**>>
**>> I am trying to work out the code to get a Fibonacci sequence, using
**>> the
**>> while() loop and only one variable. And I can't figure it out.
**>
**>
**> > phi <- 0.5 * (1 + sqrt(5))
**> > phi
**> [1] 1.618034
**> > fib <- function(n) {(phi ^ n - (1 - phi) ^ n) / sqrt(5)}
**> > fib(1:10)
**> [1] 1 1 2 3 5 8 13 21 34 55
**> >
**>
**> Admittedly this does not use a while loop as you requested
*

I like it!

> test <-c( 1, 1, 2, 3, 5, 8, 13, 21, 34, 55)
> test == fib(1:10)

** [1] TRUE TRUE TRUE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
**
To avoid such FAQ-tual puzzlement, it might be better to round to zero
digits:

fib2 <- function(n) {round( (phi ^ n - (1 - phi) ^ n) / sqrt(5) ) }

> test == fib2(1:10)

** [1] TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE
**
There are several packages that offer fib() functions of one name or
another, including the gmp package which always seems to "think
bigger" than I do. I cannot (trivially) see how that author does it
with fibnum(), because it is in a .Call()

-- DavidReceived on Thu 21 Apr 2011 - 15:48:14 GMT

>

> Courtesy of Wikipedia

>>>> Fibonacci<-c(1,1)>> while (max(Fibonacci)<500){>> Fibonacci<-c(Fibonacci, (max(Fibonacci) + ?(Fibanacci)))>> }>>>>>> How can I tell R to take the value one before the max value? (Without>> defining another variable)>>>> (Probably super easy... I am a beginner...)>>>> Thanks,>> Georgie>>>> [[alternative HTML version deleted]]>> Michael Dewey> info_at_aghmed.fsnet.co.uk> http://www.aghmed.fsnet.co.uk/home.html>> ______________________________________________> R-help_at_r-project.org mailing list> https://stat.ethz.ch/mailman/listinfo/r-help> 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 ______________________________________________ R-help_at_r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.

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