# besi1e.f

          FUNCTION BESI1E (X)
    C***BEGIN PROLOGUE  BESI1E
    C***PURPOSE  Compute the exponentially scaled modified (hyperbolic)
    C            Bessel function of the first kind of order one.
    C***LIBRARY   SLATEC (FNLIB)
    C***CATEGORY  C10B1
    C***TYPE      SINGLE PRECISION (BESI1E-S, DBSI1E-D)
    C***KEYWORDS  EXPONENTIALLY SCALED, FIRST KIND, FNLIB,
    C             HYPERBOLIC BESSEL FUNCTION, MODIFIED BESSEL FUNCTION,
    C             ORDER ONE, SPECIAL FUNCTIONS
    C***AUTHOR  Fullerton, W., (LANL)
    C***DESCRIPTION
    C
    C BESI1E(X) calculates the exponentially scaled modified (hyperbolic)
    C Bessel function of the first kind of order one for real argument X;
    C i.e., EXP(-ABS(X))*I1(X).
    C
    C Series for BI1        on the interval  0.          to  9.00000D+00
    C                                        with weighted error   2.40E-17
    C                                         log weighted error  16.62
    C                               significant figures required  16.23
    C                                    decimal places required  17.14
    C
    C Series for AI1        on the interval  1.25000D-01 to  3.33333D-01
    C                                        with weighted error   6.98E-17
    C                                         log weighted error  16.16
    C                               significant figures required  14.53
    C                                    decimal places required  16.82
    C
    C Series for AI12       on the interval  0.          to  1.25000D-01
    C                                        with weighted error   3.55E-17
    C                                         log weighted error  16.45
    C                               significant figures required  14.69
    C                                    decimal places required  17.12
    C
    C***REFERENCES  (NONE)
    C***ROUTINES CALLED  CSEVL, INITS, R1MACH, XERMSG
    C***REVISION HISTORY  (YYMMDD)
    C   770401  DATE WRITTEN
    C   890210  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   920618  Removed space from variable names.  (RWC, WRB)
    C***END PROLOGUE  BESI1E