dqelg.f
SUBROUTINE DQELG (N, EPSTAB, RESULT, ABSERR, RES3LA, NRES)
C***BEGIN PROLOGUE DQELG
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Warning: this routine is not intended to be user-callable.
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C***SUBSIDIARY
C***PURPOSE The routine determines the limit of a given sequence of
C approximations, by means of the Epsilon algorithm of
C P.Wynn. An estimate of the absolute error is also given.
C The condensed Epsilon table is computed. Only those
C elements needed for the computation of the next diagonal
C are preserved.
C***LIBRARY SLATEC
C***TYPE DOUBLE PRECISION (QELG-S, DQELG-D)
C***KEYWORDS CONVERGENCE ACCELERATION, EPSILON ALGORITHM, EXTRAPOLATION
C***AUTHOR Piessens, Robert
C Applied Mathematics and Programming Division
C K. U. Leuven
C de Doncker, Elise
C Applied Mathematics and Programming Division
C K. U. Leuven
C***DESCRIPTION
C
C Epsilon algorithm
C Standard fortran subroutine
C Double precision version
C
C PARAMETERS
C N - Integer
C EPSTAB(N) contains the new element in the
C first column of the epsilon table.
C
C EPSTAB - Double precision
C Vector of dimension 52 containing the elements
C of the two lower diagonals of the triangular
C epsilon table. The elements are numbered
C starting at the right-hand corner of the
C triangle.
C
C RESULT - Double precision
C Resulting approximation to the integral
C
C ABSERR - Double precision
C Estimate of the absolute error computed from
C RESULT and the 3 previous results
C
C RES3LA - Double precision
C Vector of dimension 3 containing the last 3
C results
C
C NRES - Integer
C Number of calls to the routine
C (should be zero at first call)
C
C***SEE ALSO DQAGIE, DQAGOE, DQAGPE, DQAGSE
C***ROUTINES CALLED D1MACH
C***REVISION HISTORY (YYMMDD)
C 800101 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 900328 Added TYPE section. (WRB)
C***END PROLOGUE DQELG