Optimization of Rational Approximations by Continued Fractions
Serdica Journal of Computing, Tome 1 (2007) no. 4, pp. 433-442
Voir la notice de l'article provenant de la source Bulgarian Digital Mathematics Library
To get guaranteed machine enclosures of a special function f(x),
an upper bound ε(f) of the relative error is needed, where ε(f) itself depends
on the error bounds ε(app); ε(eval) of the approximation and evaluation error
respectively. The approximation function g(x) ≈ f(x) is a rational function
(Remez algorithm), and with sufficiently high polynomial degrees ε(app)
becomes sufficiently small. Evaluating g(x) on the machine produces a
rather great ε(eval) because of the division of the two erroneous polynomials.
However, ε(eval) can distinctly be decreased, if the rational function g(x)
is substituted by an appropriate continued fraction c(x) which in general
needs less elementary operations than the original rational function g(x).
Numerical examples will illustrate this advantage.
Keywords:
C-XSC, Continued Fractions, Error Bounds, Special Functions
@article{SJC_2007_1_4_a3,
author = {Blomquist, Frithjof},
title = {Optimization of {Rational} {Approximations} by {Continued} {Fractions}},
journal = {Serdica Journal of Computing},
pages = {433--442},
publisher = {mathdoc},
volume = {1},
number = {4},
year = {2007},
language = {en},
url = {http://geodesic.mathdoc.fr/item/SJC_2007_1_4_a3/}
}
Blomquist, Frithjof. Optimization of Rational Approximations by Continued Fractions. Serdica Journal of Computing, Tome 1 (2007) no. 4, pp. 433-442. http://geodesic.mathdoc.fr/item/SJC_2007_1_4_a3/