COMPLEX FUNCTION CLOG10(Z)
C***BEGIN PROLOGUE  CLOG10
C***DATE WRITTEN   770401   (YYMMDD)
C***REVISION DATE  820801   (YYMMDD)
C***CATEGORY NO.  C4B
C***KEYWORDS  BASE TEN,COMPLEX,ELEMENTARY FUNCTION,LOGARITHM
C***AUTHOR  FULLERTON, W., (LANL)
C***PURPOSE  Computes the principal value of the complex base 10
C            logarithm.
C***DESCRIPTION
C
C CLOG10(Z) calculates the principal value of the complex common
C or base 10 logarithm of Z for -PI .LT. arg(Z) .LE. +PI.
C***REFERENCES  (NONE)
C***ROUTINES CALLED  (NONE)
C***END PROLOGUE  CLOG10