SLATEC Routines --- BESI0 ---

*DECK BESI0
      FUNCTION BESI0 (X)
C***BEGIN PROLOGUE  BESI0
C***PURPOSE  Compute the hyperbolic Bessel function of the first kind
C            of order zero.
C***LIBRARY   SLATEC (FNLIB)
C***CATEGORY  C10B1
C***TYPE      SINGLE PRECISION (BESI0-S, DBESI0-D)
C***KEYWORDS  FIRST KIND, FNLIB, HYPERBOLIC BESSEL FUNCTION,
C             MODIFIED BESSEL FUNCTION, ORDER ZERO, SPECIAL FUNCTIONS
C***AUTHOR  Fullerton, W., (LANL)
C***DESCRIPTION
C
C BESI0(X) computes the modified (hyperbolic) Bessel function
C of the first kind of order zero and real argument X.
C
C Series for BI0        on the interval  0.          to  9.00000D+00
C                                        with weighted error   2.46E-18
C                                         log weighted error  17.61
C                               significant figures required  17.90
C                                    decimal places required  18.15
C
C***REFERENCES  (NONE)
C***ROUTINES CALLED  BESI0E, CSEVL, INITS, R1MACH, XERMSG
C***REVISION HISTORY  (YYMMDD)
C   770401  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   900326  Removed duplicate information from DESCRIPTION section.
C           (WRB)
C***END PROLOGUE  BESI0