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Re: Finding distance with longitude and latitude [message #83986 is a reply to message #83985]

Sun, 14 April 2013 16:49

wlandsman
Messages: 743
Registered: June 2000

Senior Member

On Sunday, April 14, 2013 7:45:40 PM UTC-4, wlandsman wrote:
> On Sunday, April 14, 2013 7:22:44 PM UTC-4, gpet...@ucsc.edu wrote:
>
>
>
>> a=sqrt((cos(lat2)*sin(dlon))^2 + (cos(lat1)*sin(lat2)-sin(lat1)*cos(lat2)*cos(dlon))^2)/(sin( lat1)*sin(lat2)+cos(lat1)*cos(lat2)*cos(dlat))
>
>
>
> c= atan(a)
>
>
>
> The Wikipedia article you quote says
>
> "When programming a computer, one should use the atan2() function rather than the ordinary arctangent function (atan()), in order to simplify handling of the case where the denominator is zero, and to compute \Delta\widehat{\sigma}\;\! unambiguously in all quadrants"

I accidentally hit SEND too soon, but you want to use the two argument form of ATAN, e.g.

c = atan( numerator, denominator)

--Wayne

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[Message index]

		Re: Finding distance with longitude and latitude By: David Fanning on Tue, 16 April 2013 09:23
		Re: Finding distance with longitude and latitude By: gpeterso on Tue, 16 April 2013 08:46
		Re: Finding distance with longitude and latitude By: seanelvidge on Mon, 15 April 2013 04:13
		Re: Finding distance with longitude and latitude By: wlandsman on Sun, 14 April 2013 19:38
		Re: Finding distance with longitude and latitude By: gpeterso on Sun, 14 April 2013 18:17
		Re: Finding distance with longitude and latitude By: David Fanning on Sun, 14 April 2013 16:57
		Re: Finding distance with longitude and latitude By: wlandsman on Sun, 14 April 2013 16:49
		Re: Finding distance with longitude and latitude By: wlandsman on Sun, 14 April 2013 16:45

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