From: <apjaworski_at_mmm.com>

Date: Fri, 23 May 2008 10:19:27 -0500

Andy Jaworski

518-1-01

Process Laboratory

3M Corporate Research Laboratory

E-mail: apjaworski_at_mmm.com

Tel: (651) 733-6092

Fax: (651) 736-3122

R-help_at_r-project.org mailing list

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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. Received on Fri 23 May 2008 - 16:53:07 GMT

Date: Fri, 23 May 2008 10:19:27 -0500

Milan,

This is a fairly standard trick. Let us generalize your equation slightly:

y ~ a + c*sin(b)*cos(x) + c*cos(b)*sin(x)

Andy Jaworski

518-1-01

Process Laboratory

3M Corporate Research Laboratory

E-mail: apjaworski_at_mmm.com

Tel: (651) 733-6092

Fax: (651) 736-3122

"Zroutik Zroutik" <zroutik_at_gmail.co m> To Sent by: r-help_at_r-project.org r-help-bounces_at_r- cc project.org Subject [R] Fit a sine to data 05/23/2008 08:49 AM

Dear R-users,

I'd like to fit a sine function to my data. The result should have a format (and thus the formula, too)

y ~ a + sin(x+b)

where y and x are vectors, and a and b are (yet) unknown values.

The data sets (vectors x and y) are OK, and I can do a simple lm fitting
lm(y~x), or lm(y~I(sin(2*pi*x/360))), succesfully My issue is that I'm not
able to do the optional linear shift in x (e.g. x+b). What other
possibilities should I use instead of lm? I looked searched the R-seek for
terms: fit, sine, lm, and combinations, but I could not find anything
useful. Anybody would be so kind and point me to the right direction where
I

can find other fitting possibilities?

Thank you for listening and kind answers upfront.

Regards,

Milan

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R-help_at_r-project.org mailing list

https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide

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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. Received on Fri 23 May 2008 - 16:53:07 GMT

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