R help - Jun 2012 - Determining frequency and period of a wave

Hello!  I'm collecting data on a refrigerator that I'm using to cure
meat.  Specifically I am collection humidity and temperature readings.
The temperature readings look sinusoidal (due to the refrigerator
turning on and off).

I'd like to calculate the frequency and period of the wave so that I can
determine if modifications I make to the equipment are increasing or
decreasing efficiency.  Unfortunately, I'm pretty new to R, so I'm not
sure how to figure this out.  I *suspect* I should be doing an fft on
the temperature data, but I'm not sure where to go from there.

Here is a graph I'm producing:

  http://i.imgur.com/WpsDi.png

Here is the program I have so far:

  https://github.com/tenderlove/rsausage/blob/master/graphing.r

I have posted a repository with a SQLite database that has the data I've
collected here:
  
  https://github.com/tenderlove/rsausage

Any help would be greatly appreciated!

-- 
Aaron Patterson
http://tenderlovemaking.com/
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You could use the 'nls' function to fit a sine (or cosine) function to
the data.

On Fri, Jun 1, 2012 at 7:54 PM, Aaron Patterson
<tenderlove at ruby-lang.org> wrote:
> Hello! ?I'm collecting data on a refrigerator that I'm using to
cure
> meat. ?Specifically I am collection humidity and temperature readings.
> The temperature readings look sinusoidal (due to the refrigerator
> turning on and off).
>
> I'd like to calculate the frequency and period of the wave so that I
can
> determine if modifications I make to the equipment are increasing or
> decreasing efficiency. ?Unfortunately, I'm pretty new to R, so I'm
not
> sure how to figure this out. ?I *suspect* I should be doing an fft on
> the temperature data, but I'm not sure where to go from there.
>
> Here is a graph I'm producing:
>
> ?http://i.imgur.com/WpsDi.png
>
> Here is the program I have so far:
>
> ?https://github.com/tenderlove/rsausage/blob/master/graphing.r
>
> I have posted a repository with a SQLite database that has the data
I've
> collected here:
>
> ?https://github.com/tenderlove/rsausage
>
> Any help would be greatly appreciated!
>
> --
> Aaron Patterson
> http://tenderlovemaking.com/
>
> ______________________________________________
> 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.
>


-- 
Gregory (Greg) L. Snow Ph.D.
538280 at gmail.com