SLATEC Routines --- CATAN ---

*DECK CATAN
      COMPLEX FUNCTION CATAN (Z)
C***BEGIN PROLOGUE  CATAN
C***PURPOSE  Compute the complex arc tangent.
C***LIBRARY   SLATEC (FNLIB)
C***CATEGORY  C4A
C***TYPE      COMPLEX (CATAN-C)
C***KEYWORDS  ARC TANGENT, ELEMENTARY FUNCTIONS, FNLIB, TRIGONOMETRIC
C***AUTHOR  Fullerton, W., (LANL)
C***DESCRIPTION
C
C CATAN(Z) calculates the complex trigonometric arc tangent of Z.
C The result is in units of radians, and the real part is in the first
C or fourth quadrant.
C
C***REFERENCES  (NONE)
C***ROUTINES CALLED  R1MACH, XERMSG
C***REVISION HISTORY  (YYMMDD)
C   770801  DATE WRITTEN
C   890531  Changed all specific intrinsics to generic.  (WRB)
C   890531  REVISION DATE from Version 3.2
C   891214  Prologue converted to Version 4.0 format.  (BAB)
C   900315  CALLs to XERROR changed to CALLs to XERMSG.  (THJ)
C   900326  Removed duplicate information from DESCRIPTION section.
C           (WRB)
C***END PROLOGUE  CATAN