Public Member Functions | |
| subroutine | wp_besj (X, ALPHA, N, Y, NZ) |
| subroutine | ep_besj (X, ALPHA, N, Y, NZ) |
| Quad precision version of wp_besj. More... | |
Detailed Description
- Warning
- Quad precision version not implemented yet.
Member Function/Subroutine Documentation
◆ ep_besj()
| subroutine special_functions_gbl::cfp_besj::ep_besj | ( | real(kind=ep1) | X, |
| real(kind=ep1) | ALPHA, | ||
| integer | N, | ||
| real(kind=ep1), dimension(*) | Y, | ||
| integer | NZ | ||
| ) |
Quad precision version of wp_besj.
- Warning
- Not implemented yet.
◆ wp_besj()
| subroutine special_functions_gbl::cfp_besj::wp_besj | ( | real(kind=wp) | X, |
| real(kind=wp) | ALPHA, | ||
| integer | N, | ||
| real(kind=wp), dimension(*) | Y, | ||
| integer | NZ | ||
| ) |
***PURPOSE Compute an N member sequence of J Bessel functions
J/SUB(ALPHA+K-1)/(X), K=1,...,N for non-negative ALPHA
and X.
***LIBRARY SLATEC
***CATEGORY C10A3
***TYPE REAL(kind=wp) (BESJ-S, wp_besj-D)
***KEYWORDS J BESSEL FUNCTION, SPECIAL FUNCTIONS
***AUTHOR Amos, D. E., (SNLA)
Daniel, S. L., (SNLA)
Weston, M. K., (SNLA)
***DESCRIPTION
Abstract **** a REAL(kind=wp) routine ****
wp_besj computes an N member sequence of J Bessel functions
J/sub(ALPHA+K-1)/(X), K=1,...,N for non-negative ALPHA and X.
A combination of the power series, the asymptotic expansion
for X to infinity and the uniform asymptotic expansion for
NU to infinity are applied over subdivisions of the (NU,X)
plane. For values of (NU,X) not covered by one of these
formulae, the order is incremented or decremented by integer
values into a region where one of the formulae apply. Backward
recursion is applied to reduce orders by integer values except
where the entire sequence lies in the oscillatory region. In
this case forward recursion is stable and values from the
asymptotic expansion for X to infinity start the recursion
when it is efficient to do so. Leading terms of the series and
uniform expansion are tested for underflow. If a sequence is
requested and the last member would underflow, the result is
set to zero and the next lower order tried, etc., until a
member comes on scale or all members are set to zero.
Overflow cannot occur.
The maximum number of significant digits obtainable
is the smaller of 14 and the number of digits carried in
REAL(kind=wp) arithmetic.
Description of Arguments
Input X,ALPHA are REAL(kind=wp)
X - X .GE. 0.00_wp
ALPHA - order of first member of the sequence,
ALPHA .GE. 0.00_wp
N - number of members in the sequence, N .GE. 1
Output Y is REAL(kind=wp)
Y - a vector whose first N components contain
values for J/sub(ALPHA+K-1)/(X), K=1,...,N
NZ - number of components of Y set to zero due to
underflow,
NZ=0 , normal return, computation completed
NZ .NE. 0, last NZ components of Y set to zero,
Y(K)=0.00_wp, K=N-NZ+1,...,N.
Error Conditions
Improper input arguments - a fatal error
Underflow - a non-fatal error (NZ .NE. 0)
***REFERENCES D. E. Amos, S. L. Daniel and M. K. Weston, CDC 6600
subroutines IBESS and JBESS for Bessel functions
I(NU,X) and J(NU,X), X .GE. 0, NU .GE. 0, ACM
Transactions on Mathematical Software 3, (1977),
pp. 76-92.
F. W. J. Olver, Tables of Bessel Functions of Moderate
or Large Orders, NPL Mathematical Tables 6, Her
Majesty's Stationery Office, London, 1962.
***ROUTINES CALLED F1MACH, wp_asyjy, cfp_jairy, cfp_lngam, I1MACH, XERMSG
***REVISION HISTORY (YYMMDD)
750101 DATE WRITTEN
890531 Changed all specific intrinsics to generic. (WRB)
890911 Removed unnecessary intrinsics. (WRB)
890911 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)
900326 Removed duplicate information from DESCRIPTION section.
(WRB)
920501 Reformatted the REFERENCES section. (WRB)
Here is the call graph for this function:
The documentation for this interface was generated from the following file:
- /home/jacob/Work/codes/UKRmol/gitlab/ukrmol-in/source/gbtolib/source/special_functions.f90
