# r9knus.f

          SUBROUTINE R9KNUS (XNU, X, BKNU, BKNU1, ISWTCH)
    C***BEGIN PROLOGUE  R9KNUS
    ....
    ....
    Warning:   this routine is not intended to be user-callable.
    ....
    ....
    C***SUBSIDIARY
    C***PURPOSE  Compute Bessel functions EXP(X)*K-SUB-XNU(X) and EXP(X)*
    C            K-SUB-XNU+1(X) for 0.0 .LE. XNU .LT. 1.0.
    C***LIBRARY   SLATEC (FNLIB)
    C***CATEGORY  C10B3
    C***TYPE      SINGLE PRECISION (R9KNUS-S, D9KNUS-D)
    C***KEYWORDS  BESSEL FUNCTION, FNLIB, SPECIAL FUNCTIONS
    C***AUTHOR  Fullerton, W., (LANL)
    C***DESCRIPTION
    C
    C Compute Bessel functions EXP(X) * K-sub-XNU (X)  and
    C EXP(X) * K-sub-XNU+1 (X) for 0.0 .LE. XNU .LT. 1.0 .
    C
    C Series for C0K        on the interval  0.          to  2.50000D-01
    C                                        with weighted error   1.60E-17
    C                                         log weighted error  16.79
    C                               significant figures required  15.99
    C                                    decimal places required  17.40
    C
    C Series for ZNU1       on the interval -7.00000D-01 to  0.
    C                                        with weighted error   1.43E-17
    C                                         log weighted error  16.85
    C                               significant figures required  16.08
    C                                    decimal places required  17.38
    C
    C***REFERENCES  (NONE)
    C***ROUTINES CALLED  CSEVL, GAMMA, INITS, R1MACH, XERMSG
    C***REVISION HISTORY  (YYMMDD)
    C   770601  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   900720  Routine changed from user-callable to subsidiary.  (WRB)
    C   900727  Added EXTERNAL statement.  (WRB)
    C   920618  Removed space from variable names.  (RWC, WRB)
    C***END PROLOGUE  R9KNUS