SLATEC Routines --- BESI0E ---

*DECK BESI0E
      FUNCTION BESI0E (X)
C***BEGIN PROLOGUE  BESI0E
C***PURPOSE  Compute the exponentially scaled modified (hyperbolic)
C            Bessel function of the first kind of order zero.
C***LIBRARY   SLATEC (FNLIB)
C***CATEGORY  C10B1
C***TYPE      SINGLE PRECISION (BESI0E-S, DBSI0E-D)
C***KEYWORDS  EXPONENTIALLY SCALED, FIRST KIND, FNLIB,
C             HYPERBOLIC BESSEL FUNCTION, MODIFIED BESSEL FUNCTION,
C             ORDER ZERO, SPECIAL FUNCTIONS
C***AUTHOR  Fullerton, W., (LANL)
C***DESCRIPTION
C
C BESI0E(X) calculates the exponentially scaled modified (hyperbolic)
C Bessel function of the first kind of order zero for real argument X;
C i.e., EXP(-ABS(X))*I0(X).
C
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
C Series for AI0        on the interval  1.25000D-01 to  3.33333D-01
C                                        with weighted error   7.87E-17
C                                         log weighted error  16.10
C                               significant figures required  14.69
C                                    decimal places required  16.76
C
C
C Series for AI02       on the interval  0.          to  1.25000D-01
C                                        with weighted error   3.79E-17
C                                         log weighted error  16.42
C                               significant figures required  14.86
C                                    decimal places required  17.09
C
C***REFERENCES  (NONE)
C***ROUTINES CALLED  CSEVL, INITS, R1MACH
C***REVISION HISTORY  (YYMMDD)
C   770701  DATE WRITTEN
C   890313  REVISION DATE from Version 3.2
C   891214  Prologue converted to Version 4.0 format.  (BAB)
C***END PROLOGUE  BESI0E