8FUNCTIONS: dmean - CYANA function

Synopsis: dmean(<integer>) = <real>

This function returns the average value (in degrees) of the torsion
angle with index <integer> in the selected structures. The periodicity
of the torsion angle is considered when calculating the average
value. The average value is given by the argument of the complex
number exp(i d_1) + ... + exp(i d_n), where i denotes the imaginary
unit and d_1,...,d_n the values of the torsion angle (in radians)
in the n selected structures.

Optionally, the <integer> angle index can be replaced by a string
consisting of the angle name and the residue number, separated by a
blank or a period, '.'.
