 
      DOUBLE PRECISION FUNCTION DBESK1(X)
C***BEGIN PROLOGUE  DBESK1
C***DATE WRITTEN   770701   (YYMMDD)
C***REVISION DATE  820801   (YYMMDD)
C***CATEGORY NO.  C10B1
C***KEYWORDS  BESSEL FUNCTION,DOUBLE PRECISION,MODIFIED BESSEL FUNCTION,
C             ORDER ONE,SPECIAL FUNCTION,THIRD KIND
C***AUTHOR  FULLERTON, W., (LANL)
C***PURPOSE  Computes the dp modified Bessel function of the third kind
C            of order one.
C***DESCRIPTION
C
C DBESK1(X) calculates the double precision modified (hyperbolic)
C Bessel function of the third kind of order one for double precision
C argument X.  The argument must be large enough that the result does
C not overflow and small enough that the result does not underflow.
C
C Series for BK1        on the interval  0.          to  4.00000E+00
C                                        with weighted error   9.16E-32
C                                         log weighted error  31.04
C                               significant figures required  30.61
C                                    decimal places required  31.64
C***REFERENCES  (NONE)
C***ROUTINES CALLED  D1MACH,DBESI1,DBSK1E,DCSEVL,INITDS,XERROR
C***END PROLOGUE  DBESK1
 
 
