×

Truncation error bounds for modified continued fractions with applications to special functions. (English) Zbl 0675.65008

Let \(K(a_ n,1;x_ 1)\) be a limit-periodic modified continued fraction with \(\lim_{n\to \infty}a_ n=a\in {\mathbb{C}}-(-\infty,1/4)\) and n-th approximant \[ g_ n=S_ n(x_ 1)=a_ 1/1+a_ 2/1+...+a_{n- 1}/1+a_ n/(1+x_ 1), \] where \(x_ 1\) denotes the smaller (in modulus) of the two fixed points of \(T(w)=a/(1+w).\) Further, let \(f_ n=S_ n(0)\) be the n-th ordinary reference continued fraction \(K(a_ n/1)\). The authors give truncation error bounds for both \(g_ n\) and \(f_ n\) and show that certain a posteriori bounds for \(g_ n\) are the best possible. The paper also includes results on the speed of convergence and applications to a number of special functions. Very interesting numerical examples indicate the sharpness of the error bounds.
Reviewer: L.Gatteschi

MSC:

65D20 Computation of special functions and constants, construction of tables
30B70 Continued fractions; complex-analytic aspects
30E10 Approximation in the complex plane
41A20 Approximation by rational functions
40A15 Convergence and divergence of continued fractions

References:

[1] Baker, G.A., Jr.: Best error bounds for Pad? approximants to convergent series of Stieltjes. J. Math. Phys.10, 814-820 (1969) · Zbl 0175.36101 · doi:10.1063/1.1664911
[2] Baltus, C.: Limit-periodic continued fractions: value regions and truncation error bounds. Ph.D. Thesis, Univ. of Colorado, Boulder, CO 1984
[3] Baltus, C., Jones, W.B.: Truncation error bounds for limit-periodic continued fractionsK(a n /1) with lima n =0, Numer. Math.46, 541-569 (1985) · Zbl 0564.40002 · doi:10.1007/BF01389658
[4] Baltus, C., Jones, W.B.: A family of best value regions for modified continued fractions. In: Thron, W.J. (ed.), pp. 1-20. Analytic theory of continued fractions II. Lect. Notes Math. 1199. Berlin Heidelberg New York: Springer 1986 · Zbl 0595.30005
[5] Blanch, G.: Numerical evaluation of continued fractions. SIAM Rev.7, 383-421 (1964) · Zbl 0133.38904 · doi:10.1137/1006092
[6] Brezinski, C.: On the asymptotic behavior of continued fractions. Universit? des sciences et techniques de Lille, Publication ANO-172 (1987)
[7] Brezinski, C., Lembarki, A.: The linear convergence of limit periodic continued fractions, J. Comput. Appl. Math.19, 75-77 (1987) · Zbl 0662.30003
[8] Elliott, D.: Truncation errors in Pad? approximations to certain functions: An alternative approach. Math. of Comput.21, 398-406 (1967) · Zbl 0158.06701
[9] Field, D.A.: Error bounds for elliptic convergence regions for continued fractions, SIAM J. Numer. Anal.15, 444-449 (1978) · Zbl 0383.65016 · doi:10.1137/0715028
[10] Field, D.A., Jones, W.B.: A priori estimates for truncation error of continued fractionsK(1/b n ). Numer. Math.19, 283-302 (1972) · Zbl 0227.65004 · doi:10.1007/BF01404877
[11] Gill, J.: Truncation error analysis for continued fractionsK(a n /1) where \(\sqrt {|a_n |} + \sqrt {|a_{n - 1} |}< 1\) . Lect. Notes in Math., No. 932. Jones, W.B., Thron, W.J., Waadeland, H. (eds.) Springer-Verlag (1982), 71-73
[12] Gragg, W.B.: Truncation error bounds forg-fractions. Numer. Math.11, pp. 370-379 (1968) · Zbl 0177.43202 · doi:10.1007/BF02161885
[13] Gragg, W.B.: Truncation error bounds for ?-fractions. Bull. Amer. Math. Soc.76, 1091-1094 (1970) · Zbl 0201.39204 · doi:10.1090/S0002-9904-1970-12574-5
[14] Gragg, W.B.: Truncation error bounds forT-fractions. In: Approximation Theory III, pp. 455-460. Cheney, W. (ed.). New York: Academic Press 1980
[15] Henrici, P., Pfluger, P.: Truncation error estimates for Stieltjes fractions. Numer. Math.9, 120-138 (1966) · Zbl 0152.15301 · doi:10.1007/BF02166031
[16] Jacobsen, L.: Some periodic sequences of circular convergence regions. Lect. Notes Math.932, 87-98 (1982) · Zbl 0497.30006 · doi:10.1007/BFb0093308
[17] Jacobsen, L.: Convergence acceleration and analytic continuation by means of modifications of continued fractions. Kong. Norske Vid. Selsk. Skr.1, 19-33 (1983) · Zbl 0628.30002
[18] Jacobsen, L.: Modified approximants for continued fractions. Construction and applications, Kong. Norske Vid. Selsk. Skr,3, 1-46 (1983)
[19] Jacobsen, L.: Convergence of limitk-periodic continued fractionsK(a n /b n ) and of subsequences of their tails. Proc. London Math. Soc.51, 563-576 (1985) · doi:10.1112/plms/s3-51.3.563
[20] Jacobsen, L.: General convergence of continued fractions. Trans. Amer. Math. Soc.294, 477-485 (1986) · Zbl 0587.40002 · doi:10.1090/S0002-9947-1986-0825716-1
[21] Jacobsen, L., Jones, W.B., Waadeland, H.: Further results on the computation of incomplete gamma functions. In: Thron, W.J. (ed.). Analytic theory of continued fractions II, pp. 67-89, Lect. Notes Math. 1199. Berlin Heidelberg New York: Springer 1986 · Zbl 0597.33002
[22] Jacobsen, L., Thron, W.J.: Oval convergence regions and circular limit regions for continued fractionsK(a n /1). In: Throm W.J. (ed.). Analytic theory of continued fractions II, pp. 90-126, Lect. Notes Math. 1199. Berlin Heidelberg New York: Springer 1986 · Zbl 0594.40001
[23] Jefferson, T.H.: Truncation error estimates forT-fractions SIAM J. Numer. Anal.6, 359-364 (1969) · Zbl 0183.44004 · doi:10.1137/0706033
[24] Jones, W.B.: Multiple point Pad? tables. In: Saff, E.B., Varga, R.S. (eds.). Pad? and rational approximation, pp. 163-171. New York: Academic Press, 1977
[25] Jones, W.B., Snell, R.I.: Truncation error bounds for continued fractions. SIAM J. Numer. Anal.6, 210-221 (1969) · Zbl 0185.40602 · doi:10.1137/0706019
[26] Jones, W.B., Thron, W.J.: A posteriori bounds for the truncation error of continued fractions. SIAM J. Numer. Anal.8, 693-705 (1971) · doi:10.1137/0708063
[27] Jones, W.B., Thron, W.J.: Truncation error analysis by means of approximant systems and inclusion regions. Numer. Math.26, 117-154 (1976) · Zbl 0313.65040 · doi:10.1007/BF01395969
[28] Jones, W.B., Thron, W.J.: Continued fractions: Analytic theory and applications. Encyclopedia of mathematics and its applications 11th Ed. Reading, MA: Addison-Wesley (1980); distributed now by Cambridge University Press, New York · Zbl 0445.30003
[29] Jones, W.B., Thron, W.J.: Continued fractions in numerical analysis. Appl. Num. Math.4, 143-230 (1988) · Zbl 0654.65002 · doi:10.1016/0168-9274(83)90002-8
[30] Perron, O.: Die Lehre von den Kettenbr?chen, Band II. Stuttgart: Teubner 1957 · Zbl 0077.06602
[31] Poincar?, H.: Sur les equations lin?aires aux diff?rentielles ordinaires et aux diff?rences finies. Amer. J. Math.7, 205-258 (1885) · JFM 17.0290.01
[32] Sweezy, W.B., Thron, W.J.: Estimates of the speed of convergence of certain continued fractions. SIAM J. Numer. Anal.4, 254-270 (1967) · Zbl 0153.46702 · doi:10.1137/0704024
[33] Thron, W.J.: On parabolic convergence regions for continued fractions. Math. Z.69, 173-182 (1958) · Zbl 0081.05704 · doi:10.1007/BF01187398
[34] Thron, W.J.: A priori truncation error estimates for Stieltjes fractions. In: Butzer, P.L., Feh?r, F., Christoffel, E.B., (eds.) pp. 203-211. Basel: Aachen Birkh?user 1981 · Zbl 0472.30008
[35] Thron, W.J., Waadeland, H.: Accelerating convergence of limit periodic continued fractionsK(a n /1). Numer. Math.34, 155-170 (1980) · doi:10.1007/BF01396057
[36] Thron, W.J., Waadeland, H.: Truncation error bounds for limit periodic continued fractions. Math. Comput.40, 589-597 (1983) · Zbl 0517.30006 · doi:10.1090/S0025-5718-1983-0689475-9
This reference list is based on information provided by the publisher or from digital mathematics libraries. Its items are heuristically matched to zbMATH identifiers and may contain data conversion errors. In some cases that data have been complemented/enhanced by data from zbMATH Open. This attempts to reflect the references listed in the original paper as accurately as possible without claiming completeness or a perfect matching.