cpsi.f
COMPLEX FUNCTION CPSI (ZIN)
C***BEGIN PROLOGUE CPSI
C***PURPOSE Compute the Psi (or Digamma) function.
C***LIBRARY SLATEC (FNLIB)
C***CATEGORY C7C
C***TYPE COMPLEX (PSI-S, DPSI-D, CPSI-C)
C***KEYWORDS DIGAMMA FUNCTION, FNLIB, PSI FUNCTION, SPECIAL FUNCTIONS
C***AUTHOR Fullerton, W., (LANL)
C***DESCRIPTION
C
C PSI(X) calculates the psi (or digamma) function of X. PSI(X)
C is the logarithmic derivative of the gamma function of X.
C
C***REFERENCES (NONE)
C***ROUTINES CALLED CCOT, R1MACH, XERMSG
C***REVISION HISTORY (YYMMDD)
C 780501 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 900727 Added EXTERNAL statement. (WRB)
C***END PROLOGUE CPSI