Get angle between vectors in radians or degrees

Get the angle between two vectors specified by their end points using law of cosines. Vector 1 is defined as the vector pointing from the point (x1_i, y1_i) to (x1_f, y1_f) and vector 2 is defined as the vector point from the point (x2_i, y2_i) to (x2_f, y2_f). The angle is defined as the angle produced if the two vectors are joined at the initial endpoints (rather than head-to-tail). The resulting angle is always positive.

Usage

get_angle_between_vectors(
  x1_i,
  y1_i,
  x1_f,
  y1_f,
  x2_i,
  y2_i,
  x2_f,
  y2_f,
  degrees = F
)

Arguments

x1_i

x coordinate of initial point of vector 1

y1_i

y coordinate of initial point of vector 1

x1_f

x coordinate of final point of vector 1

y1_f

y coordinate of final point of vector 1

x2_i

x coordinate of initial point of vector 2

y2_i

y coordinate of initial point of vector 2

x2_f

x coordinate of final point of vector 2

y2_f

y coordinate of final point of vector 2

degrees

if T, angle will be returned in degrees (otherwise it will be returned in radians)

Value

Returns the angle between the two specified vectors

Author

Ariana Strandburg-Peshkin

NOT YET CODE REVIEWED