This topic contains 9 replies, has 6 voices, and was last updated by 
Team Black-Cat 15 years, 11 months ago.
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How do I determine the distance between two sets of coordinates by using math, not a GPS? Doing this will help me on the way to solve a puzzle. Thanks 🙂
You can use the program FizzyCalc (free) to do this for you. once you have the program I believe what you are looking for is under the distance tab.
If you are working on the puzzle that I think you are working on, pay close attention to the description and hints. Some people’s view of the world is skewed, similar to that of people in the 12th century. I wonder if they were worried about sailing off the edge of the world!
Unless you REALLY need to do the math, you should probably find an online utility to get the distance.
But since you asked…
I recently created a function for a program I’m working on. Here’s what I did.
Keep in mind that I am a programmer and not a mathmatician…Start with decimal degrees instead of degrees and minutes. You can do the conversion on GC.com.
Convert each coordinate to radians:
A=(Point1Latitude * Pi /180)
B=(Point1Longitude * Pi /180)
C=(Point2Latitude * Pi /180)
D=(Point2Latitude * Pi /180)Get the difference between the angles:
DLat=C-A
DLon=D-BNow it gets fun…
X = Sin(DLat / 2) * Sin(DLat / 2) + Cos(A) * Cos(C) * Sin(DLon / 2) * Sin(DLon / 2)
Y = 2 * Atan2(Sqrt(X), Sqrt(1 - X))To get miles, multiply Y by 3959.
Did I get it right Mathman?
Edited to add:
Atan2 might not be on your calculator. It is the angle whose tanget is the quotent of the two specified numbers.@Team Black-Cat wrote:
A=(Point1Latitude * Pi /180)
B=(Point1Longitude * Pi /180)
C=(Point2Latitude * Pi /180)
D=(Point2Latitude * Pi /180)I assume you meant Point2Longitude for D.
Yes I did, and thanks for catching that. I can’t edit the original post anymore…
For a whole bunch of different versions of this, do a “Google” search using the following words:
gps distance calculator@codejunkie wrote:
For a whole bunch of different versions of this, do a “Google” search using the following words:
gps distance calculatorIf you’re having trouble sleeping, search for “haversine”.
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