I am relatively new to R, so this may be a much simpler question than it seems to me. I am trying to create a function that includes two summations, and can't figure out how. I am attaching the equation as a pdf file. This function will then be optimized over a chosen range of values, but right now I just need help with the function. Thank you. Zack Darnell Duke University -- Zack Darnell Duke University Marine Lab 135 Duke Marine Lab Rd. Beaufort, NC 28516 Tel: (252) 732-5727 Email: mzd2 at duke.edu -------------- next part -------------- A non-text attachment was scrubbed... Name: equation.pdf Type: application/pdf Size: 10971 bytes Desc: not available Url : https://stat.ethz.ch/pipermail/r-help/attachments/20071017/45109be4/attachment.pdf
Romain Francois
2007-Oct-17 12:35 UTC
[R] Need help with function that includes 2 summation
Zack Darnell wrote:> I am relatively new to R, so this may be a much simpler question than > it seems to me. I am trying to create a function that includes two > summations, and can't figure out how. I am attaching the equation as a > pdf file. This function will then be optimized over a chosen range of > values, but right now I just need help with the function. Thank you. > Zack Darnell > Duke UniversityHi, I'm a bit unsure of what you call double summation, I only see the i index in here, you can almost translate the latex code into R: R> sqrt( sum(cos(k*theta))^2 + sum(sin(k*theta))^2 ) / n theta being a vector containing all your theta_i, for i in 1 to n. Cheers, Romain -- Mango Solutions data analysis that delivers Tel: +44(0) 1249 467 467 Fax: +44(0) 1249 467 468 Mob: +44(0) 7813 526 123
Henrique Dallazuanna
2007-Oct-17 12:54 UTC
[R] Need help with function that includes 2 summation
Perhaps:
r <- function(n, k, theta){
return(sqrt((sum(cos(k*theta))^2 + sum(sin(k*theta))^2)/n))
}
On 17/10/2007, Zack Darnell <mzd2@duke.edu> wrote:>
> I am relatively new to R, so this may be a much simpler question than it
> seems to me. I am trying to create a function that includes two
> summations, and can't figure out how. I am attaching the equation as a
> pdf file. This function will then be optimized over a chosen range of
> values, but right now I just need help with the function. Thank you.
> Zack Darnell
> Duke University
>
> --
> Zack Darnell
> Duke University Marine Lab
> 135 Duke Marine Lab Rd.
> Beaufort, NC 28516
>
> Tel: (252) 732-5727
> Email: mzd2@duke.edu
>
>
> ______________________________________________
> R-help@r-project.org mailing list
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> PLEASE do read the posting guide
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> and provide commented, minimal, self-contained, reproducible code.
>
>
>
--
Henrique Dallazuanna
Curitiba-Paraná-Brasil
25° 25' 40" S 49° 16' 22" O
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