besi1.f
FUNCTION BESI1 (X)
C***BEGIN PROLOGUE BESI1
C***PURPOSE Compute the modified (hyperbolic) Bessel function of the
C first kind of order one.
C***LIBRARY SLATEC (FNLIB)
C***CATEGORY C10B1
C***TYPE SINGLE PRECISION (BESI1-S, DBESI1-D)
C***KEYWORDS FIRST KIND, FNLIB, HYPERBOLIC BESSEL FUNCTION,
C MODIFIED BESSEL FUNCTION, ORDER ONE, SPECIAL FUNCTIONS
C***AUTHOR Fullerton, W., (LANL)
C***DESCRIPTION
C
C BESI1(X) calculates the modified (hyperbolic) Bessel function
C of the first kind of order one for real argument 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***REFERENCES (NONE)
C***ROUTINES CALLED BESI1E, CSEVL, INITS, R1MACH, XERMSG
C***REVISION HISTORY (YYMMDD)
C 770401 DATE WRITTEN
C 890531 Changed all specific intrinsics to generic. (WRB)
C 890531 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***END PROLOGUE BESI1