The cosine spiral transition segment is a special case of a spiral where the curvature rate of change is a cosine function and the terms are dependent on the length L measured from the inflection point. The parameter value is defined as the deflection i.e. bearing angle &Theta.
The values of its individual terms dependent on segment length L:
CosineTerm = L
Constant = 1
The following diagram shows the generic classes and relationships used when applying this concept.