rotatieterm

Rotatieterm is a term sometimes used in Dutch-language mathematical and computer-science literature to denote the parameter that controls rotation in a transformation. The word combines rotatie (rotation) and term, and while it is not a universal formal term in English, it appears as a descriptive label for the angle or angle-like quantity that specifies how far a object is rotated relative to a reference frame.

In two dimensions, a rotation by an angle θ about the origin is described by the rotation matrix [ [cos θ, -sin θ], [sin θ, cos θ] ]; the rotatieterm in this formula is θ. In three dimensions, rotations can be represented in several ways (axis-angle, Euler angles, quaternions). The rotatieterm is the angle θ that defines the magnitude of the rotation around the chosen axis in axis-angle form, or one of the three angles in Euler-angle decompositions.

Practically, the rotatieterm is typically expressed in radians or degrees and is used alongside other transformation parameters such as translation and scaling in affine or rigid-body transformations. Its exact interpretation depends on the chosen representation and the coordinate system conventions; for example, different conventions may exchange the order of rotations or select different axes for Euler angles.

See also: rotation matrix, Euler angles, axis-angle representation, quaternions, homogeneous transformation.