[Swlug] Math Calculations

[terry at happysoft.co.uk]

Just had a quick look. Does it assume a flat Earth? If so the triangle  
should be fairly simple (Even if the code is not.. haha )

Terry

Quoting Rhys Sage via Swlug <swlug at mailman.lug.org.uk>:

> I've been working on some maths problems. I can honestly say I  
> detest maths when it gets complicated and usually end up relying  
> upon easy solutions found online.
>
> I found the solution to calculating compass headings online and it  
> seems pretty  believable. The distance however, I'm not sure I have  
> right. I've calculated it on diameter of the earth over 90. I had it  
> over 360 originally but since it's 450km from the Arc de Triomphe to  
> the Tower of London the small figure of 77 miles didn't seem right.  
> Thus I tried 180 and that wasn't right either. 90 is a more  
> believable figure but even so I think it's likely wrong. Does  
> anybody have any navigational expertise to throw in here?
>
> #!/usr/bin/env python3
> # -*- coding: utf-8 -*-
> """
> Created on Tue Jul 19 12:04:26 2022
>
>
> @author: rhys
> """
> import math
> DiameterOfEarth = 7917.5
>
>
> #Assumung two fixed point - just for the sake of making life easy...
> #North = positive values. South = negative values
> #West = Positive values, East = negative values
> LocationOneV = 51.5081
> LocationOneH = 0.0759
> #Tower of London
>
>
> LocationTwoV = 48.8738
> LocationTwoH = -2.2950
> #Arc de Triomph
>
>
> X = math.cos(LocationTwoV)*math.sin(LocationOneH-LocationTwoH)
> Y = (math.cos(LocationOneV)*math.sin(LocationTwoV)-math.sin(LocationOneV)*
>     math.cos(LocationTwoV)*math.cos(LocationOneH-LocationTwoH))
>
>
> Z = math.atan2(X,Y)  #radians
>
> #Compass heading in degrees
> Degrees = math.degrees(Z)
> print (Z)
>
>
> #Distance calculation
> DistanceV = (LocationOneV - LocationTwoV)
> DistanceH = (LocationOneH - LocationTwoH)
> DistanceCalc = (DistanceV*DistanceV)+(DistanceH*DistanceH)
> ActualDistance = math.sqrt(DistanceCalc)*(DiameterOfEarth / 90)
>
> #Distance to go in miles
> print(ActualDistance)
>
>
>
> Rhys Sage
>
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