DBSI1E(3)

SYNOPSIS
DOUBLE PRECISION FUNCTION DBSI1E (X)

NAME
dbsi1e - Compute the exponentially scaled modified (hyperbolic) Bessel function of the first kind of order one.

LIBRARY
SLATEC (FNLIB)

CATEGORY
C10B1

TYPE
DOUBLE 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
DBSI1E(X) calculates the double precision exponentially scaled modified (hyperbolic) Bessel function of the first kind of order one for double precision argument X. The result is I1(X) multiplied by EXP(-ABS(X)). Series for BI1 on the interval 0. to 9.00000E+00 with weighted error 1.44E-32 log weighted error 31.84 significant figures required 31.45 decimal places required 32.46 Series for AI1 on the interval 1.25000E-01 to 3.33333E-01 with weighted error 2.81E-32 log weighted error 31.55 significant figures required 29.93 decimal places required 32.38 Series for AI12 on the interval 0. to 1.25000E-01 with weighted error 1.83E-32 log weighted error 31.74 significant figures required 29.97 decimal places required 32.66

REFERENCES
(NONE)

ROUTINES CALLED
D1MACH, DCSEVL, INITDS, XERMSG

REVISION HISTORY (YYMMDD)
770701 DATE WRITTEN
890531 Changed all specific intrinsics to generic. (WRB)
890531 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)