bearing between two points

How can i calculate the bearing or the angular relationship between two points in a form in terms of degrees

Aren't two points always connected by a straight line? So it could be 0, 180, 360...

Quote:

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Originally Posted by RhinoBull

Aren't two points always connected by a straight line? So it could be 0, 180, 360...

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That's right.
You'll need a third point (or vector) to get an angle.

This gives the bearing from one point on a flat 2D plane to another point, relative to the plane's 'north'.

vb Code:

Public Const Pi  As Double = 3.14159265358979
Public Const Pi2 As Double = 3.14159265358979 * 2#
 
Public Const DegRad As Double = 3.14159265358979 / 180#
Public Const RadDeg As Double = 180# / 3.14159265358979
 
Public Function ATan2(ByVal X As Double, ByVal Y As Double) As Double
Dim sY As Double
Dim sX As Double
    If Y < 0# Then sY = -Pi Else sY = Pi
    If X = 0# Then
        ATan2 = sY * 0.5
    Else
        If X < 0# Then sX = sY Else sX = 0#
        ATan2 = Atn(Y / X) + sX
    End If
'    If ATan2 < 0 Then ATan2 = ATan2 + Pi2
End Function

X and Y are the relative dX and dY between both points.
The positive Y axis is north, the positive X axis is east.
The result is in radians.
Multiply by RadDeg to get the result in degrees.
(multiply by DegRad to do the opposite)


If you are working on the surface of a sphere or in 3D space then you'll need different methods.

Thanks i will try it out