I\'m trying to compute the angle between two vectors. I tried this, but it always returns zero:
public double GetAngle(Vector2 a, Vector2 b)
{
double angle = Mat
I think code show as below copy from .NET source code could help you.
reference: http://referencesource.microsoft.com/#WindowsBase/Base/System/Windows/Vector.cs,102
/// <summary>
/// AngleBetween - the angle between 2 vectors
/// </summary>
/// <returns>
/// Returns the the angle in degrees between vector1 and vector2
/// </returns>
/// <param name="vector1"> The first Vector </param>
/// <param name="vector2"> The second Vector </param>
public static double AngleBetween(Vector vector1, Vector vector2)
{
double sin = vector1._x * vector2._y - vector2._x * vector1._y;
double cos = vector1._x * vector2._x + vector1._y * vector2._y;
return Math.Atan2(sin, cos) * (180 / Math.PI);
}
since you use vector2 class, I guess you can use
a-b
to get the vector from a to b.
so the angle you need is: Pi - angle(a-b).
You have to use the difference in x and y inside of the Atan2 method:
Math.Atan2(b.Y - a.Y,b.X - a.X);
Also, I believe this will give you the angle from 0
to the hypotenuse of the triangle you've provided (not entirely sure).
I'd suggest trying Math.PI - angle
.
You should take a look at the documentation of atan2
(here).
What you're looking of is finding the difference between B (your upper left vector) and A (your bottom right vector), then pass this as a parameter to atan2
return Math.Atan2(b.Y - a.Y,b.X - a.X);
What your code currently does is find the angle of the vector b
in reference to 0,0
and subtract the angle of the vector a
in reference to 0,0
.
The reason you always get 0 is because 1,1
and 50,50
are on the same line that crosses 0,0
(both calls return something approx. 0.785398
), so subtracting them will result in 0
I'm a bit late to the party, but how about the static method on the Vector class:
Vector.AngleBetween(vector1, vector2)
if you are looking for the "angle between vectors a and b", you want the delta of the angle for vector a and the angle for vector b:
Math.Atan2(b.Y, b.X) - Math.Atan2(a.Y, a.X)
But the diagram doesn't match "angle between vectors". The answer for the diagram is indeed the previous answer given:
Math.Atan2(b.Y - a.Y, b.X - a.X)