*DECK ASYJY SUBROUTINE ASYJY (FUNJY, X, FNU, FLGJY, IN, Y, WK, IFLW) C***BEGIN PROLOGUE ASYJY C***SUBSIDIARY C***PURPOSE Subsidiary to BESJ and BESY C***LIBRARY SLATEC C***TYPE SINGLE PRECISION (ASYJY-S, DASYJY-D) C***AUTHOR Amos, D. E., (SNLA) C***DESCRIPTION C C ASYJY computes Bessel functions J and Y C for arguments X.GT.0.0 and orders FNU.GE.35.0 C on FLGJY = 1 and FLGJY = -1 respectively C C INPUT C C FUNJY - external function JAIRY or YAIRY C X - argument, X.GT.0.0E0 C FNU - order of the first Bessel function C FLGJY - selection flag C FLGJY = 1.0E0 gives the J function C FLGJY = -1.0E0 gives the Y function C IN - number of functions desired, IN = 1 or 2 C C OUTPUT C C Y - a vector whose first in components contain the sequence C IFLW - a flag indicating underflow or overflow C return variables for BESJ only C WK(1) = 1 - (X/FNU)**2 = W**2 C WK(2) = SQRT(ABS(WK(1))) C WK(3) = ABS(WK(2) - ATAN(WK(2))) or C ABS(LN((1 + WK(2))/(X/FNU)) - WK(2)) C = ABS((2/3)*ZETA**(3/2)) C WK(4) = FNU*WK(3) C WK(5) = (1.5*WK(3)*FNU)**(1/3) = SQRT(ZETA)*FNU**(1/3) C WK(6) = SIGN(1.,W**2)*WK(5)**2 = SIGN(1.,W**2)*ZETA*FNU**(2/3) C WK(7) = FNU**(1/3) C C Abstract C ASYJY implements the uniform asymptotic expansion of C the J and Y Bessel functions for FNU.GE.35 and real C X.GT.0.0E0. The forms are identical except for a change C in sign of some of the terms. This change in sign is C accomplished by means of the flag FLGJY = 1 or -1. On C FLGJY = 1 the AIRY functions AI(X) and DAI(X) are C supplied by the external function JAIRY, and on C FLGJY = -1 the AIRY functions BI(X) and DBI(X) are C supplied by the external function YAIRY. C C***SEE ALSO BESJ, BESY C***ROUTINES CALLED I1MACH, R1MACH C***REVISION HISTORY (YYMMDD) C 750101 DATE WRITTEN C 890531 Changed all specific intrinsics to generic. (WRB) C 891009 Removed unreferenced variable. (WRB) C 891214 Prologue converted to Version 4.0 format. (BAB) C 900328 Added TYPE section. (WRB) C 910408 Updated the AUTHOR section. (WRB) C***END PROLOGUE ASYJY