besi0e.f
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