FUNCTION COT(X)
C***BEGIN PROLOGUE  COT
C***DATE WRITTEN   770601   (YYMMDD)
C***REVISION DATE  820801   (YYMMDD)
C***CATEGORY NO.  C4A
C***KEYWORDS  COTANGENT,ELEMENTARY FUNCTION
C***AUTHOR  FULLERTON, W., (LANL)
C***PURPOSE  Computes the Cotangent.
C***DESCRIPTION
C
C COT(X) calculates the cotangent of the real argument X.  X is in
C units of radians.
C
C Series for COT        on the interval  0.          to  6.25000D-02
C                                        with weighted error   3.76E-17
C                                         log weighted error  16.42
C                               significant figures required  15.51
C                                    decimal places required  16.88
C***REFERENCES  (NONE)
C***ROUTINES CALLED  CSEVL,INITS,R1MACH,XERROR
C***END PROLOGUE  COT