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| subroutine | wp_asyjy (FUNJY, X, FNU, FLGJY, IN, Y, WK, IFLW) |
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| subroutine | ep_asyjy (FUNJY, X, FNU, FLGJY, IN, Y, WK, IFLW) |
| | Quad precision version of wp_asyjy. More...
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- Warning
- Quad precision version not implemented yet.
◆ ep_asyjy()
| subroutine special_functions_gbl::cfp_asyjy::ep_asyjy |
( |
external |
FUNJY, |
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real(kind=ep1) |
X, |
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real(kind=ep1) |
FNU, |
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real(kind=ep1) |
FLGJY, |
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integer |
IN, |
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real(kind=ep1), dimension(*) |
Y, |
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real(kind=ep1), dimension(*) |
WK, |
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integer |
IFLW |
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) |
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Quad precision version of wp_asyjy.
◆ wp_asyjy()
| subroutine special_functions_gbl::cfp_asyjy::wp_asyjy |
( |
external |
FUNJY, |
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real(kind=wp) |
X, |
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real(kind=wp) |
FNU, |
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real(kind=wp) |
FLGJY, |
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integer |
IN, |
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real(kind=wp), dimension(*) |
Y, |
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real(kind=wp), dimension(*) |
WK, |
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integer |
IFLW |
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) |
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***SUBSIDIARY
***PURPOSE Subsidiary to cfp_besj and DBESY
***LIBRARY SLATEC
***TYPE REAL(kind=wp) (ASYJY-S, wp_asyjy-D)
***AUTHOR Amos, D. E., (SNLA)
***DESCRIPTION
wp_asyjy computes Bessel functions J and Y
for arguments X.GT.0.0 and orders FNU .GE. 35.0
on FLGJY = 1 and FLGJY = -1 respectively
INPUT
FUNJY - External subroutine JAIRY or YAIRY
X - Argument, X.GT.0.00_wp
FNU - Order of the first Bessel function
FLGJY - Selection flag
FLGJY = 1.00_wp gives the J function
FLGJY = -1.00_wp gives the Y function
IN - Number of functions desired, IN = 1 or 2
OUTPUT
Y - A vector whose first IN components contain the sequence
IFLW - A flag indicating underflow or overflow
return variables for BESJ only
WK(1) = 1 - (X/FNU)**2 = W**2
WK(2) = SQRT(ABS(WK(1)))
WK(3) = ABS(WK(2) - ATAN(WK(2))) or
ABS(LN((1 + WK(2))/(X/FNU)) - WK(2))
= ABS((2/3)*ZETA**(3/2))
WK(4) = FNU*WK(3)
WK(5) = (1.5*WK(3)*FNU)**(1/3) = SQRT(ZETA)*FNU**(1/3)
WK(6) = SIGN(1.,W**2)*WK(5)**2 = SIGN(1.,W**2)*ZETA*FNU**(2/3)
WK(7) = FNU**(1/3)
Abstract **** A REAL(kind=wp) Routine ****
wp_asyjy implements the uniform asymptotic expansion of
the J and Y Bessel functions for FNU.GE.35 and real
X.GT.0.00_wp. The forms are identical except for a change
in sign of some of the terms. This change in sign is
accomplished by means of the flag FLGJY = 1 or -1. On
FLGJY = 1 the Airy functions AI(X) and DAI(X) are
supplied by the external function JAIRY, and on
FLGJY = -1 the Airy functions BI(X) and DBI(X) are
supplied by the external function YAIRY.
***SEE ALSO cfp_besj, DBESY
***ROUTINES CALLED F1MACH, I1MACH
***REVISION HISTORY (YYMMDD)
750101 DATE WRITTEN
890531 Changed all specific intrinsics to generic. (WRB)
890911 Removed unnecessary intrinsics. (WRB)
891004 Correction computation of ELIM. (WRB)
891009 Removed unreferenced variable. (WRB)
891214 Prologue converted to Version 4.0 format. (BAB)
900328 Added TYPE section. (WRB)
910408 Updated the AUTHOR section. (WRB)
The documentation for this interface was generated from the following file:
