Marc Mezzarobba

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We describe an algorithm that takes as input a complex sequence (un) given by a linear recurrence relation with polynomial coecients along with initial values, and outputs a simple explicit upper bound (vn) such that |un| ≤ vn for all n. Generically, the bound is tight, in the sense that its asymptotic behaviour matches that of un. We discuss applications(More)
We introduce a software-oriented algorithm that allows one to quickly compare a binary64 floating-point (FP) number and a decimal64 FP number, assuming the "binary encoding" of the decimal formats specified by the IEEE 754-2008 standard for FP arithmetic is used. It is a two-step algorithm: a first pass, based on the exponents only, makes it possible to(More)
We describe the main features of the Dynamic Dictionary of Mathematical Functions (version 1.5). It is a website consisting of interactive tables of mathematical formulas on elementary and special functions. The formulas are automatically generated by computer algebra routines. The user can ask for more terms of the expansions, more digits of the numerical(More)
—We introduce an algorithm to compare a binary floating-point (FP) number and a decimal FP number, assuming the " binary encoding " of the decimal formats is used, and with a special emphasis on the basic interchange formats specified by the IEEE 754-2008 standard for FP arithmetic. It is a two-step algorithm: a first pass, based on the exponents only,(More)
Le problème étudié J'ai travaillé sur l'évaluation à grande précision des fonctions holonomes par scindage bi-naire. Le scindage binaire est une technique simple et très efficace en pratique pour calculer (entre autres) des sommes de séries en tirant profit de la multiplication rapide des grands entiers. Son application à l'évaluation et au prolongement(More)
The series expansion at the origin of the Airy function Ai(x) is alternating and hence problematic to evaluate for x > 0 due to cancellation. Based on a method recently proposed by Gawronski, Müller, and Rein hard, we exhibit two functions F and G, both with nonnegative Taylor expansions at the origin, such that Ai(x) = G(x)/F(x). The sums are(More)
Let (f 1 ,. .. , f s) be polynomials in Q[X 1 ,. .. , X n ] of degree bounded by D that generate a radical equidimensional ideal of dimension d and let V ⊂ C n be the locus of their complex zero set which is supposed to be smooth. A roadmap in V ∩ R n is a real algebraic curve contained in V ∩ R n which has a non-empty and connected intersection with each(More)
We present a new open source implementation in the Sage-Math computer algebra system of algorithms for the numerical solution of linear ODEs with polynomial coefficients. Our code supports regular singular connection problems and provides rigorous error bounds. Extended abstract for a talk given at the 5th International Congress on Mathematical Software(More)