SLATEC Routines --- BESI1E ---


*DECK BESI1E
      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