SLATEC Routines --- DBESK0 ---

*DECK DBESK0
      DOUBLE PRECISION FUNCTION DBESK0 (X)
C***BEGIN PROLOGUE  DBESK0
C***PURPOSE  Compute the modified (hyperbolic) Bessel function of the
C            third kind of order zero.
C***LIBRARY   SLATEC (FNLIB)
C***CATEGORY  C10B1
C***TYPE      DOUBLE PRECISION (BESK0-S, DBESK0-D)
C***KEYWORDS  FNLIB, HYPERBOLIC BESSEL FUNCTION,
C             MODIFIED BESSEL FUNCTION, ORDER ZERO, SPECIAL FUNCTIONS,
C             THIRD KIND
C***AUTHOR  Fullerton, W., (LANL)
C***DESCRIPTION
C
C DBESK0(X) calculates the double precision modified (hyperbolic)
C Bessel function of the third kind of order zero for double
C precision argument X.  The argument must be greater than zero
C but not so large that the result underflows.
C
C Series for BK0        on the interval  0.          to  4.00000E+00
C                                        with weighted error   3.08E-33
C                                         log weighted error  32.51
C                               significant figures required  32.05
C                                    decimal places required  33.11
C
C***REFERENCES  (NONE)
C***ROUTINES CALLED  D1MACH, DBESI0, DBSK0E, DCSEVL, INITDS, XERMSG
C***REVISION HISTORY  (YYMMDD)
C   770701  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***END PROLOGUE  DBESK0