COTAN (real-number)

  Class:  Elemental function - Generic

  Returns the cotangent of the argument.

  The argument cannot be zero.  It must be in radians and is treated
  as modulo 2*pi.

  +------+---------+----------+------------+-------------+
  | Args | Generic | Specific |  Argument  | Result Type |
  +------+---------+----------+------------+-------------+
  |   1  | COTAN   | COTAN    | REAL*4     | REAL*4      |
  |      |         | DCOTAN   | REAL*8     | REAL*8      |
  |      |         | QCOTAN   | REAL*16    | REAL*16     |
  +------+---------+----------+------------+-------------+