[R] Transformation of the circular variable into linear variable

[Martin Maechler]

>>>>> David Winsemius <dwinsemius at comcast.net>
>>>>>     on Tue, 5 May 2015 08:41:08 -0700 writes:

    > On May 5, 2015, at 3:59 AM, Nasr Al-Dhurafi wrote:

    >> Dear All
    >> 
    >> I am working with a circular data ( wind direction ) and i have problem
    >> in transforming  the circular variable into linear variable. I have found
    >> an equation that can be used to convert the circular variable into linear
    >> variable which is included in this paper *" ARMA based approaches for
    >> forecasting the tuple of wind speed and direction". *The equation is called
    >> as the inverse of a link function and i have attached  the summery of it.T
    >> herefore,Please, if you have an idea of how to conduct it in R programming
    >> or  if you have another method for transformation, let me know it. Your
    >> cooperation is highly appreciated.
    >> 
    >> My Best Regards &  All The Best

    > Here are a couple of plausible explanations for a lack of response to your first message posted 2 months ago:

    > Neither of your duplicate messages have any attachments. This could be caused by the fact (buried away in one or more of webpages or Posting Guides that define the Rhelp facility)  the information that the mail-server used by the Rhelp list strips any attachments unless they are one of the limited number accepted file formats. (It does not notify posters of htis fact when they submit unacceptable formats.)  The 4 formats I know to be accepted are: MIME-text, .pdf, .ps or .png. Even if you submit formats that you might think would be considered "text", they will not be accepted if they have non-".txt" extensions such as ".csv". As far as I can tell ... only .txt extensions are passed through.

Thanks a lot, David, for helping Nasr (and many others)!

The above explantion is not quite accurate though and I want to make sure
correct info gets archived here:  The file extension does not
play any role for the mailing list server software, which is "mailman".
Mailman -- rightly -- only looks at the declared MIME type of the attachment.
("MIME": see https://en.wikipedia.org/wiki/MIME).

Now with 99.x% of people using e-mail software which does not
reveal any of these subtle details to you, and many such e-mail
interfaces behaving like Windows programs, that e-mail software may choose
the MIME type (it uses for the attachments it puts into the
e-mail it sends in your behalf) depending on the file extension.
So, from the naive user's point of view with his only e-mail
program he may know, it then seems as if the file extension
determines the acceptance of the attachment by the mailman rules
we have had imposed (for spam and virus protection).

Martin Maechler
ETH Zurich

    >> I find an article by that name in Applied Energy Volume 88, Issue 4, April 2011, Pages 1405–1414. The publisher offers a copy at the price of 42 USD. (Expecting us to buy that article seems unreasonable.)

    > Most of us are not meteorological researchers. In general list members are more likely to respond to requests that include a) sample data, b) code that reflects your efforts, and c) a specification of correct output. It may be helpful to list details of your position.

    > -- 
    > David.

    >> 
    >> Nasr
    >> 
    >> On Mon, Mar 30, 2015 at 8:22 PM, Nasr Al-Dhurafi <ldhrf at siswa.ukm.edu.my>
    >> wrote:
    >> 
    >>> I am working with a circular data ( wind direction ) and i have problem
    >>> in transforming  the circular variable into linear variable. I have found
    >>> an equation that can be used to convert the circular variable into linear
    >>> variable which is included in this paper *" ARMA based approaches for
    >>> forecasting the tuple of wind speed and direction". *The equation is
    >>> called as the inverse of a link function and i have attached  the summery
    >>> of it.Therefore,Please, if you have an idea of how to conduct it in R
    >>> programming or  if you have another method for transformation, let me
    >>> know it. Your cooperation is highly appreciated.
    >>> 
    >>> My Best Regards &  All The Best
    >>> Nasr
    >>> 
    >> 
    >> [[alternative HTML version deleted]]
    >> 
    >> ______________________________________________
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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
    > Alameda, CA, USA

    > ______________________________________________
    > R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
    > 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.