BESI1E(3)

SYNOPSIS
FUNCTION BESI1E (X)

NAME
besi1e - Compute the exponentially scaled modified (hyperbolic) Bessel function of the first kind of order one.

LIBRARY
SLATEC (FNLIB)

CATEGORY
C10B1

TYPE
SINGLE PRECISION (BESI1E-S, DBSI1E-D)

KEYWORDS
EXPONENTIALLY SCALED, FIRST KIND, FNLIB, HYPERBOLIC BESSEL FUNCTION, MODIFIED BESSEL FUNCTION, ORDER ONE, SPECIAL FUNCTIONS

AUTHOR
Fullerton, W., (LANL)

DESCRIPTION
BESI1E(X) calculates the exponentially scaled modified (hyperbolic) Bessel function of the first kind of order one for real argument X; i.e., EXP(-ABS(X))*I1(X). Series for BI1 on the interval 0. to 9.00000D+00 with weighted error 2.40E-17 log weighted error 16.62 significant figures required 16.23 decimal places required 17.14 Series for AI1 on the interval 1.25000D-01 to 3.33333D-01 with weighted error 6.98E-17 log weighted error 16.16 significant figures required 14.53 decimal places required 16.82 Series for AI12 on the interval 0. to 1.25000D-01 with weighted error 3.55E-17 log weighted error 16.45 significant figures required 14.69 decimal places required 17.12

REFERENCES
(NONE)

ROUTINES CALLED
CSEVL, INITS, R1MACH, XERMSG

REVISION HISTORY (YYMMDD)
770401 DATE WRITTEN
890210 REVISION DATE from Version 3.2
891214 Prologue converted to Version 4.0 format. (BAB)
900315 CALLs to XERROR changed to CALLs to XERMSG. (THJ)
900326 Removed duplicate information from DESCRIPTION section. (WRB)
920618 Removed space from variable names. (RWC, WRB)